The Invisible-Box Murders

Being made of fairly good cellophane—ten cents a sheet in the dime stores—it was transparent. Not as transparent, perhaps, as good window glass, but you could see through it without trouble.

It was approximately half the size of a shoe box; as wide and as high as a shoe box, but only half as long. Otherwise, it bore no resemblance to a shoe box. The lid was not the same. This lid was a kind of flap.

It looked, as nearly as Doc Savage had been able to make it look, exactly like the newspaper photographs, and the police photographs, of the other boxes.

So it looked like the invisible boxes. Not like the invisible boxes, exactly. But at least like the invisible boxes looked before they became invisible. Those that had been photographed.

It was a little complicated. Or more specifically, baffling. Baffling was the word.

Doc Savage was putting the box on a man’s doorstep.

It was a little more complicated than that, of course. Getting into the building had not been entirely simple. It was an office building, the time was near the noon hour, and the place was crowded with people who might recognize Doc Savage. He knew this. The people were not personal acquaintances and no one he had met, but there just might be someone who might recognize his picture from the newspapers. So he had come in through the freight entrance and walked up eleven flights of stairs.

He had stood on the eleventh floor, in the hall, for twenty minutes. Rather, he had occupied a broom closet, with the door opened a crack, for that long.

J. P. MORGAN

Investments

That was what it said on the door.

It was not the J. P. Morgan, however. This one’s name was not Pierpont, and he was not an international banker, or a private banker at all. He was just a buyer and seller of cheap securities of the type called cats and dogs. And he was not very prosperous.

Some detective work by Andrew Blodgett Monk Mayfair, associate of Doc Savage, had unearthed that much about this J. P. Morgan.

Finally, the secretary had gone out to lunch.

Monk Mayfair had explained that the secretary wasn’t very pretty. That undoubtedly meant she was as homely as a mud fence with the hide of an octopus tacked on it. Monk Mayfair was easily affected by women; and when he thought one was homely, she was homely indeed.

This was right. The secretary wasn’t attractive. She looked hungry and in a hurry. She hadn’t locked the office door behind her, which indicated that J. P. Morgan was in.

Doc Savage had wanted Mr. Morgan to be in. He walked to the door, opened it and entered, careful to make no sound.

The reception room was furnished with a desk, an uncomfortable chair, a telephone—these for the secretary—and a seedy and once-luxurious divan for clients.

Doc put the cellophane box on the desk. He picked up the telephone, connected it to the inner room, pressed the key and got a man’s voice in answer. Presuming this was Mr. Morgan, Doc Savage spoke rapidly. Doc was a man of many unusual capabilities, and one of these was the ability to imitate voices, even a woman’s voice after a fashion.

Because, being quite masculine, he could not exactly duplicate the secretary’s voice exactly, he used a whisper instead.

He said, whispering, "A package just came for you, Mr. Morgan."

The voice said, "Bring it in."

"You better come out and get it," Doc said.

Then he got out of the office, closed the door to a half-inch aperture and waited to see what would happen.

He had put the cellophane box on the stenographer’s desk; so he hadn’t literally left the box on the man’s doorstep.

J. P. MORGAN came out of the inner office almost immediately.

In looks, Mr. Morgan was an old gentleman of surprising benevolence. He was of less than average height, more than average width. His hair was very white, his whiskers very silky and as white as his hair. He had fawnlike brown eyes with little crinkles at the corners.

Peace and good will; I love my brother. That was Mr. Morgan.

Mr. Morgan looked around the office, then saw the cellophane box.

He proceeded—if one should want to put it humorously—to have kittens.

His eyes seemed to be trying to get out of his skull. That was the first thing, as he looked at the box. Then he made a noise. It was the noise of a man caught under a freight train.

He jumped backward wildly. His eyes hunted for a weapon. He snatched a fire extinguisher off the wall and squirted the extinguisher contents at the box.

He did not go near the box, or try to put it on the floor. He just squirted the extinguisher stream at it. The pencil of tetrachloride—or whatever was in the extinguisher—knocked the cellophane box off the desk, and it fell to the floor.

The scared Mr. Morgan kept squirting until the extinguisher was empty. He threw the extinguisher at the box, missing it.

Then he proceeded to try to burn the box. He dumped the contents of the wastebasket on it, struck a match and applied it to the paper. He didn’t seem to give a hoot about whether the shabby rug got a hole burned in it or not.

Fortunately or unfortunately, the stream of fluid from the extinguisher had soaked the contents of the wastebasket, so the paper wouldn’t burn.

First he had tried to extinguish it; now he was trying to burn it. This was rather silly. It showed only one thing: Mr. Morgan was so scared he didn’t know whether he was standing on his head or on his feet.

Then it dawned on him that the cellophane box was empty. He bent over, staring at the box. He looked utterly relieved. He sank back in the stenographer’s chair so loosely and so helplessly that the chair upset, scooting out from under him and depositing him on the floor. He sat there on the floor like a man who had been nearly knocked out.

Doc Savage walked into the office.

"It might be advisable for you to tell me why seeing that box excited you so," Doc said.

MORGAN stood up so straight that he seemed to lift an inch off the floor. He looked at the window as if he wanted to jump out of it.

"Oh, hello," he said vaguely.

Doc Savage moved toward him, saying, "Mr. Morgan, I presume."

This was purely a conversational statement because Monk Mayfair had described Mr. Morgan, and this was he.

The old gentleman looked at the doors as if he wanted to dash out through them, and at the stenographer’s desk as if he wished to crawl under it.

"I . . . er . . . beg your pardon," he said.

Doc Savage took him by the arm. He did not resist. Doc led him into the inner office. The place was furnished with a desk, filing cabinet, an uncomfortable chair behind the desk for Mr. Morgan, and a less comfortable one in front of the desk—exactly the reverse, in comfort degree, of the arrangement in the outer office. Doc sat him down in the chair.

The bronze man went to the outer office, then returned with what was left of the cellophane box. He put this on the desk in front of Mr. Morgan.

"Why did it excite you?" he asked.

Morgan swallowed, and the ends of his fingers twitched as if they were in cold water.

He was not going to talk.

Doc Savage was a big man, so big that his real size was startlingly apparent whenever he stood close to an ordinary object, such as a chair or a desk. His skin was deeply bronzed, and his eyes like liquid gold under narrowed lids. He was, in whole, a striking figure. Strength seemed to flow like molten metal under every square inch of his skin.

Doc said, "Four men have died. Four that the police know of, and there have been many others."

Morgan began turning white.

Doc continued, "The deaths have mystified the police. There seemed to be no reason for any of them and no connection between the four deaths."

Morgan started trembling.

"They were not natural deaths," added Doc Savage. "Each one was mysterious, unexplained—and are still unexplained. The leading scientists of the police department were baffled, and the consulting experts called in on the cases are baffled."

The white-haired man’s breathing now became audible. It was a sound like cloth tearing deep within him, a soft and low sound, but disturbing.

Doc said, "A box was found near each dead man. In each case, it was a box, presumably made of cellophane."

Morgan opened and closed his mouth.

"The boxes later vanished," Doc said. "They disappeared completely and inexplicably, and no one seems to be able to explain just what did happen to them. It is very mystifying to the police."

Morgan took hold of his lip with his teeth, very tightly.

"The newspapers are referring to them as invisible boxes," Doc added.

Morgan’s paleness, trembling and strained breathing had all combined until he now looked and acted like a man about to fall into fragments.

Doc Savage made what was obviously his final statement in his summary.

"All of the mysteriously dead men," he said, "happened to be acquaintances of yours, Mr. Morgan. That is a matter which the police were not fortunate enough to discover."

The white-haired man broke.

FOR something more than five minutes, he alternately sobbed, clenched and unclenched his fists, or pounded wildly on the desk in front of him. He jumped up, or attempted to do so several times, as if he wanted to run screaming from the place. In each case, Doc Savage restrained him.

But finally, he said, "I am only Uncle Joe Morgan. Why should anyone want to do such things to me?"

Doc Savage took a chair, the uncomfortable one. His eyes, which had been narrowed, seemed to relax, so that the lids widened. His eyes were like pools of flake gold stirred by tiny winds.

"So you do know something about the affair," he said.

Uncle Joe Morgan shuddered. It was the fifteenth time, at least, that he had shuddered. But this time he did it violently.

"I am a gentle man," he said.

"I have no enemies because I am not an ambitious man." He moved a hand vaguely, indicating his office. "I make a very modest living, dealing in low-priced, but sound, stocks, bonds and commodities. I have no bad habits. My only hobby is boating, and practically my only piece of property is a small schooner which I own."

Doc Savage studied him.

"Which is all preliminary to your saying what?" he asked.

Uncle Joe Morgan swallowed with great difficulty. "I have realized the coincidence of each of those men being an acquaintance of mine," he said. "And it has frightened me. As far as I know, those men who have died have had no connection with each other, except that they knew me!"

"Which means?"

"I . . . I would give everything to know. All I own." Uncle Joe Morgan clenched his hands. "I mean that."

Doc Savage indicated the cellophane box. "Seeing that box disturbed you a great deal."

The other man bowed his white head. "I know. I have just told you why."

Doc Savage said nothing. His metallic features, rugged and well-molded so that they were handsome without being in any sense pretty-pretty, showed no expression. His face gave an impression of controlled power.

"You seemed very scared," he said.

The other straightened. "You do not believe me?"

"You were unusually disturbed," Doc said.

Uncle Joe Morgan took out a handkerchief, wiped his face.

"I give you my word I know nothing about this," he said. "I am just unnerved by those deaths. Those men were not extremely close to me, but I knew them quite well. They have died one after another, in that weird fashion, and it has terrified me. Just the men I know are dying? Why is that?"

"You cannot explain it?"

"No."

"You might try to think of something."

Uncle Joe Morgan’s lips were paper-white and his breathing had, all during their talk, become more and more like cloth tearing. The tearing had started, seemingly, deep in his lungs, so that it was barely audible; now, it was up in his throat, and loud.

"I have thought about it," he said, "for four straight days and nights. I have not slept."

Doc Savage arose. There had been no sound audible to normal ears. But the bronze man went to the reception room door, opened it; and the homely secretary was there. She looked up curiously at Doc Savage and then, fascinated by the unusual power which the bronze man radiated, as people always were, kept staring at him.

He closed the door and went back to the desk. He put both hands on the desk. The sinews in the backs of the hands stood out like steel pencils.

"What about Ted Parks?" he asked. Then, when the old man seemed to melt in his chair: "So you’ve thought of that, too?"

"You mean—Ted Parks also knew the men who have died?"

"Yes."

"I . . . I knew that."

"We had better talk to Ted Parks," Doc Savage said.

"He . . . he has disappeared."

"Yes," Doc said. "So we discovered."

"Look." Uncle Joe Morgan reached into his desk and brought out an envelope. From the envelope he took a paper, which he spread on the desk. "Look," he repeated.

It read:

I am coming to see you at four o’clock Friday. You better be there, and you better not tell anybody I am coming. AND I MEAN NOBODY.

Bughide.

"Ted Parks wrote that. Today is Friday. So he is coming at four o’clock today." Uncle Joe Morgan drew in a deep breath. "That name he signed to it, Bughide, is a nickname I called Ted one time. I think he has always resented it. I called him the name because he is so easily offended. I think I referred to him having a hide no thicker than a bug, at the time."

Doc Savage looked at the note in silence for a while.

He asked, "Have you any objections to my being present at four o’clock this afternoon when Ted Parks pays you this call?"

The white-haired man sat up straight.

"I would be delighted," he said.

"Have you any idea why the note has this violent tone?" Doc asked. "The reference, in particular, that you had better not tell anyone."

"I have no idea."

"Expect me shortly before four o’clock," Doc Savage said.

DOC SAVAGE left the office building and stepped into a nearby restaurant. He took a seat in a booth in the rear, a booth with high wooden partitions in front and behind.

A man was already seated in the booth. He was a short, wide man covered with rusty-red hair. He had sloping shoulders, no forehead worth mentioning and a face that was something to start dogs barking.

This pleasantly apish fellow had a pig under the table. The pig was sitting there in comfort, one eye on the proprietor of the restaurant, who did not look happy.

"Well, did he admit getting the note from Parks?" asked the man.

"Yes, Monk, he admitted that," Doc Savage said. "But he admitted to very little else."

Monk Mayfair grinned. "That’s a point in his favor. I don’t reckon he could have known I went through his mail and gave that letter a go-over with Long Tom’s pet portable X-ray machine."

Doc Savage asked, "Is Long Tom on the job?"

"Yes," Monk said. "He has tapped Uncle Joe Morgan’s telephone line and put a recording instrument on it."

"And Renny?"

"Renny has rented an office across the street. He is sitting there with a pair of binoculars, watching the inside of Uncle Joe’s office."

"Ham?"

Monk sniffed, as if he did not care for Ham. Ham was Brigadier General Theodore Marley "Ham" Brooks, noted lawyer, one of Doc Savage’s five assistants. Monk’s sniffing about Ham was misleading. They were like brothers, and they never let a day pass—and seldom an hour—without a quarrel.

"Ham," said Monk, "has gone to hire a good, trustworthy lip reader to sit in the office with Renny and read the lips of Uncle Joe Morgan, or any visitors he has, with the binoculars."

"The situation seems to be taken care of," Doc Savage said.

"From this end, it is."

The bronze man arose. "Contact me at headquarters if necessary."

Monk nodded. "O. K. By radio. Right."

Doc Savage left. The restaurant proprietor was wiping his hands on his apron and glaring at the pig under Monk’s table.

It was then one o’clock.

Chapter II. GIRL BRINGING TROUBLE

AT two o’clock, the frantic girl came to Doc Savage.

He was, at the time, on the eighty-sixth floor of a midtown skyscraper. The floor was divided into three rooms—a reception room, a library and a laboratory. Doc was engaged in preparing plates of nutrient media for a bacteriological research he was conducting.

One of his assistants was presiding over the reception room. The assistant was Brigadier General Theodore Marley Brooks, called Ham by everyone because he hated pork, hogs, and anything swine, wild or tame. Ham was an eminent lawyer. The Harvard legal alumni were very proud of him. He was considered one of the great legal minds.

He was not engaged in a deep legal problem at the moment, however.

He was teaching his pet chimpanzee, named Chemistry, to tie one end of a string to an object, then tie the other end of the same string to a different object. Ham was getting a great deal of glee out of this teaching, chuckling as if he had something devilish in mind.

The frantic girl arrived suddenly. She began beating on the door and screaming!

Like that. Suddenly. One moment Doc was tinkering with nutrient media and Ham was teaching his chimp to tie strings and there was an amiable silence. Then the screeching; the pounding of fists on the door.

Ham bolted to his feet. Chemistry, the chimp, made a brown streak to safety under the nearest desk. In the lab, Doc Savage put the slide of nutrient media in a temperature-controlled vacuum case as if nothing had happened.

The girl’s words were mostly garbled.

But she was telling someone to, "Get away from me!"

Ham Brooks had been associated with Doc Savage long enough to know better than to take chances. He leaped to an inlaid desk, jammed a finger against an inlay which was a concealed button and caused a sheet of bulletproof glass, as clear as any plate glass, to drop between himself and the door. He punched another button which opened the door.

Wasted precaution. The girl was actually in trouble. If not, it was a very real imitation because the man who was fighting her seemed to be doing his best to get his knife into her throat! The knife had a blade the size of a razor, somewhat the same shape.

Had he been a larger man, the girl’s yelling and struggling would have ended by now. He was not large. The two were, in fact, about a match in strength, and the girl had hold of the knife arm with both hands.

Ham leaped forward. In his chivalrous haste, he forgot all about just lowering the glass panel. He got his nose flattened. He went around the glass, pain twisting his face, and charged.

The small man saw Ham coming. He dropped his knife, so the girl would release his arm. She did so. The man ran. Ham galloped after him.

The man realized he would be overtaken. As soon as he understood that, he whirled, drawing a gun. It was an automatic, huge and flat, with dark bulk.

He aimed the gun at Ham and fired. And part of the top came off his head, not off Ham’s head.

THE girl—she was not bad to look at, at first glance, and she improved on acquaintance—made a mewing sound and closed her eyes from the bottom up. She fell loosely and lay on the floor, beside the knife.

Doc Savage came out of the reception room into the hall. He took one glance. Then he went back inside the reception room, leaped to the inlaid desk and pressed several curlicues of inlay which were buttons.

As a result of the buttons he pressed, all elevators in the building stopped, the stairways were flooded with a gas—not tear gas, but one that would produce unconsciousness through its ability to be absorbed by the skin pores—and the armed elevator starters in the ornate lobby received a warning flash of signal light.

Then Doc returned to the hall.

Ham was bending over the body of the small man. He had picked up the gun, what was left of it.

"Really," he remarked.

Doc Savage took the weapon. He picked up several fragments which had blown off it and examined these.

"The gun was fixed to kill the man," he said.

Then he sank to a knee beside the small man.

"Dead?" Ham asked.

Doc nodded. He went to the girl.

"Just fainted, didn’t she?" Ham asked.

Again Doc nodded.

"I never saw either one of them before," Ham said. He got down and went through the pockets of the dead man. They were empty. He looked inside the clothing for labels. There were no labels. He searched for laundry marks. None of those, either.

"That’s strange," Ham remarked. "You hear of murderers taking the labels out of their victims’ pockets so they can’t be identified. But I never heard of a guy walking around with the labels out of his clothes. He sure didn’t want to be identified in case we caught him."

A purse lay near the girl. Doc picked it up, went through the contents. There was the usual woman stuff. No name, however, on anything.

The girl had brown hair, brown eyes, nice mouth, a turned-up nose. Faces of women who have fainted are usually loose, colorless and unlovely. But this face was firm, composed, even beautiful.

There was no question but that she was in a genuine faint, not faking. Doc made sure of that.

"Certainly strange, these labels missing," Ham said again.

Doc Savage indicated the remains of the gun.

"This weapon," he said, "had been deliberately tampered with so that it would kill anyone who fired it."

Ham’s eyes widened.

"Say, Doc, that makes it look as if someone gave him the gun so that, if he got in a jam and tried to use it, he would kill himself. Kind of an automatic elimination, as it were."

The bronze man nodded.

They carried the girl inside, and Doc worked over her with resuscitating materials.

Ham went to the big inlaid desk, pulled out a drawer and examined an array of signal lights. He used a telephone which connected with the elevators and the elevator starters on the ground floor.

"This fellow doesn’t seem to have had anyone with him," Ham reported. "At least, we caught nobody."

The girl opened her eyes.

"I don’t know why they took my brother," she said.

Ham Brooks was aware that he jumped and that Doc Savage showed no emotion. Doc’s self-control always amazed Ham, although he had known the bronze man a long time.

"Who took your brother?" Doc asked.

"They will kill him!" she said.

Her voice was charged with horror.

Patiently, Doc inquired, "Who?"

She got hold of herself. "I am . . . my name is Jeanette Bridges. Jen, they call me. You are Doc Savage. You were pointed out to me, once, from a distance. I was told at the time that you follow the rather strange career of righting wrongs and punishing evildoers; that you help people who are in trouble. I need your help."

She did not say this in one breath, but it had that effect.

"Who was the man outside?" Doc Savage asked.

She closed her eyes and shuddered tremendously. "That man—he was the one who warned me. You see, I am an artist. I do fashion layouts for department stores. I take orders in the morning and work in the afternoons. Today I came back to my home a little after one o’clock, and four men were taking my brother away. I realized something was wrong. I confronted them with a demand to know what was going on." She stopped. Her hands trembled. "My brother suddenly burst out in a wild rush of words."

"Your brother’s name?"

"David."

"And these wild words were?"

"That the four men were going to kill him—kill my brother!"

"What happened?"

"The four men dragged my brother away. Later that . . . that man out in the hall came back. He said there was something big and terrible involved. He said I should keep my mouth shut about what had happened to my brother. He said I was to forget I ever had a brother. He said it would be too bad for me if I didn’t. And after he told me all that, he went away."

"And then you did what?"

"I thought of you," she said. "I came here. That man must have followed me. He set upon me with the knife in the hall."

Doc Savage’s eyes became more alive, alert.

"Was an invisible box mentioned?" he inquired.

"A what? What do you mean—invisible box?"

"You do not seem to have read the newspapers."

"Ordinarily, I do. But the last few days I have been too busy."

"You are an artist?"

"Yes."

Doc Savage went away and came back with drawing paper, pencils and erasers.

"Sketch the faces of those four men—or the three who are still alive—as best you can from memory," he said. "Also, sketch their figures and any details about their clothing."

The girl went to work, drawing rapidly. She was good.

HAM BROOKS stared at the line drawing the girl had finished and said, "By Jove! Wait a moment!" Suddenly excited, he sprang to his feet, and went to a filing cabinet. He began hunting frantically.

Doc Savage had been watching the drawing. He glanced at Ham, said, "In the A file, Ham. He is filed under Acquaintances."

Ham found a sheaf of papers. He came back, put a paper under the girl’s nose. It had an ordinary newspaper photograph pasted to it.

She stared. "That’s him!" she ejaculated. "That’s one of the men!"

The cutlines under the picture, the print identifying the subject of the photograph, read:

Elmer I. Ivers, banker, who says the foreign situation will improve.

Jen Bridges jabbed a finger excitedly at the picture. "That was one of the men. How did you happen to have his picture?"

The man in the photograph had wide, thin eyes, a nose that turned up until the nostrils were visible only as two holes, and a thatch of hair that was like the top of an oat shock in general shape. Thick horn-rimmed spectacles gave him an additional distinction.

"How do you happen to have this?" the girl asked.

Ham glanced at Doc, and the bronze man shook his head very slightly.

Ham said to the girl, "Oh, we keep a file of such stuff. A kind of rogue’s gallery."

Jen Bridges looked around the room at the library and laboratory which showed through open doors. She seemed impressed.

Doc Savage went to a small portable radio, put it in operation. "Monk," he said into the microphone.

Monk, the homely fellow with the pet pig, had a squeaking, ridiculous voice that might have belonged to a small child.

"Yes," he said over the radio.

"Has Uncle Joe Morgan left his office?" Doc inquired.

"No."

"Has he telephoned anyone?"

"Not a soul since you left him, Long Tom says."

"Or received any calls?"

"Not a one," Monk reported.

"Keep a close watch on him and advise me if he makes a move, places a telephone call or receives any, or has visitors, dispatches, messengers—anything he does."

"Right."

The bronze man switched off the radio apparatus. "Miss Bridges," he said, "do you know a Mr. J. P. Morgan?"

"I don’t move in those financial circles," Jen said.

"Not that one. This one calls himself Uncle Joe Morgan."

She shook her head immediately. "I do not know him."

"And did, or do you, know Elmer I. Ivers?"

"Who is he?"

"A businessman and banker. He controls the Iverson Chemical Co."

"No, I do not know him," she said. "Except, of course, he was one of the men who seized my brother. I can see that from the picture of him. But that is all I know about him."

"Do you mind staying here with Mr. Brooks?" Doc asked.

"No, I don’t mind," she said.

Doc Savage moved into the laboratory and began getting equipment together and stuffing it into his pockets. Ham followed him to the door and watched.

"You are going to investigate Ivers?" Ham asked.

"That is right," Doc said.

Ham glanced back at the girl. He came into the laboratory and closed the door so she could not overhear him.

"Elmer Ivers is one of the men we investigated in connection with the mystery of the invisible boxes," Ham said.

"He happened to know two of the victims," Doc Savage agreed. "But Uncle Joe Morgan is the only man we have been able to locate who knew all victims."

Ham started. "Say, doesn’t Uncle Joe Morgan know Elmer Ivers, too?"

"He does."

Doc Savage finished collecting gadgets which he might or might not need in the course of the investigation he planned.

As he was leaving, the girl asked, "Are you going to help find my brother?"

"You can be sure of that," Doc told her.

SOMEONE shot at him as he was leaving the building!

The shot came from a distance and evidently from a single-shot silenced rifle, equipped with a telescopic sight. It was probably a rifle with a small bore and fantastic velocity—on the order of a .220 Swift, .219 Zipper, or .22 Hi-Power—judging from the way the bullet hit. The pill of lead, not as large as a bean, was capable of stunning like a stick of dynamite.

Doc was able to judge the type of bullet from what it did to the bulletproof glass of his car window. It practically demolished the outer coat of the glass, which should shatter, and put a big depression in the window.

Doc stopped the car instantly. He did not roll down the window. He waited. No more bullets came. His flake-gold eyes moved unceasingly.

There were at least a thousand windows in the adjacent batteries of great buildings from which the shot could have come. But nowhere could he detect anything.

Cars blew horns impatiently behind him. He drove on.

Into the radio, he said, "Ham, someone with a good rifle, someone who can shoot well, is watching the building."

Ham said, "I will get hold of Johnny and Pat and have them take a look. It begins to seem that we have stuck our noses into something that is pretty well organized."

"Leave Pat out of it," Doc said.

"All right," Ham agreed.

Pat was Patricia Savage, a young lady who loved excitement. She was Doc Savage’s cousin; and, because she was entertaining as well as a handy gadget to have around when there was trouble, the others liked to work with her. Doc also liked to work with Pat. But he considered most of their business too dangerous for a girl.

Chapter III. WHAT THE GIRL BROUGHT

DOC SAVAGE did not, ordinarily, go out of his way to hunt trouble, but the present case was an exception.

The big bronze man had been trained from childhood—a weird sort of upbringing, with his being placed in the hands of scientists from childhood onward for development—for the business of righting wrongs and punishing evildoers. The training was the idea of his parents; and the results had been remarkable, as far as making a physical marvel and a mental genius out of Doc.

It was a plan on the part of his parents which could easily have gone wrong and warped the bronze man’s character, his disposition, even his soul.

Privately—and the psychologists agreed with him on this point—Doc considered the thing a dangerous experiment which could easily have failed. Or worse, it might have created a kind of human monster.

Fortunately, Doc had inherited a love of excitement and a sense of humor. So the training had been eminently successful. Many people had come to him for help, and he had aided some; while others, undeserving, or who had sought to use his genius to help line their pockets, had received a painful education.

He had hordes of enemies.

He was proud of them.

He had a great many more friends.

He had gone into the mystery of the invisible boxes because it was intriguing and because the police seemed to be making no headway. He had entered it thoroughly, beginning with a complete investigation of all possibilities, which was how he happened to learn of Elmer Ivers.

Ivers, being a wealthy man, lived in eccentric fashion on board a ferryboat.

Not a ferry which plied across New York harbor. This one was out of service, tied up to a dock off fashionable Sutton Place, near the impressive shadow of Queensboro Bridge.

The ferryboat home of Ivers had received a splash of newspaper publicity from time to time, because of its human quality. Ivers, it seemed, had started business life as a huckster of peanuts, popcorn and crackerjack on this identical ferryboat, many years ago. Since, he had grown rich, purchased the old boat and rebuilt it into a bizarre home.

DOC SAVAGE parked his car near the boat. He had driven cautiously and indirectly, keeping a watch on the traffic to make sure he was not being followed.

Afternoon sun was behind the high Manhattan buildings, a few clouds loitered like lambs in the sky, and river traffic moved lazily.

The bronze man used the boldest course. He walked to the dock, strode out on the gangplank and reached the entrance of the ferryboat. He knocked. No answer.

There was a foghorn of the hand-operated type which was obviously intended to double as a doorbell. He gave it a whirl. The thing bellowed like a bull.

Footsteps came to the door, and the door opened.

The man had a turned-up nose, a thatch of hair like the top of an oat shock, thick horn-rimmed spectacles. His clothing was good, expensive. There was a brown stain on the spotless front of his dress shirt, as if a pipe had drooled there.

"I am sorry," he said. "The servants are away for the afternoon."

Doc said, "Ivers?"

The other blinked behind the spectacles. "Yes, I am Elmer Ivers."

"Doc Savage," Doc said.

"I have heard of you."

"May I come in?"

"If you wish."

The man led Doc Savage to a room. It could not be called a cabin, although it was on the ferryboat; it was a room—large, comfortable, a reception office of some kind, evidently, because there were no windows.

There were two doors, one by which they had entered and another, directly opposite.

"Will you wait a moment?" Ivers said. "I left some eggs frying, and I had better—"

He stepped toward the other door as he spoke. Doc knew, then, that plenty was wrong. He jumped for the man. But the other was fast on his feet. He raced through the doorway and slammed the door shut.

Doc Savage hit the door, and it was too solid. He went back and hit the other door, the one by which he had entered. That one was locked, and also solid.

The man began screaming, then. His voice began at a high pitch, and lost tone, then volume. It was like a siren dying down, except that the shrieking was not a continuous sound but a series of rending screeches in descending scale.

The voice silenced.

The whole boat seemed to become full of running feet.

Doc Savage produced an object the size of a cherry from a pocket—it looked a little like a black cherry, of steel—and thrust the tapered stem into the lock of the outer door. Then he got back.

He held his mouth wide open to lessen the concussion when the "cherry" let go. It soon did, with blue flame, awful noise, and violence enough to make the door look as if a dozen axes had worked upon it.

Doc Savage went through the opening.

Men appeared before him.

He looked at them and stopped.

"The fellow went through this other door," he said.

The men were policemen, most of them uniformed. They had guns and tear gas and determined expressions. One of them Doc Savage knew.

"Lieutenant Blosser," Doc said, "the man went through that door, yonder. As soon as he was on the other side, he began screaming."

Lieutenant Blosser said, "We heard the cries, Mr. Savage." He went to the door.

"It is locked," Doc Savage said.

Lieutenant Blosser took hold of the knob, and the door opened. It was not locked. He glanced at Doc Savage queerly. Then he went into the room.

At once, he reappeared. His face was grim.

He said, "Mr. Savage, you say a man ran in here?"

"Yes."

"A man with a turned-up nose, thick horn-rimmed spectacles, tangled straw-colored hair?"

"Yes."

He ran into this room and began screaming?"

"Yes."

"Did you follow him into the room?"

"No."

Lieutenant Blosser compressed his lips. "Have you been in this other room?"

"No."

"You are sure of that?"

Doc Savage’s metallic features were expressionless, but his flake-gold eyes seemed puzzled. "Why are you skeptical, lieutenant?" he asked.

Lieutenant Blosser stepped back.

"Come in here and see for yourself," he said.

Doc did so. The room had no windows. The only door was the one by which they had entered. There was no means of leaving or entering the room, in fact, except by the door.

A man was dead on the floor. A stubby man with thick spectacles, matted hair, and a nose turned up to show its nostrils.

A cellophane box stood beside the dead man!

LIEUTENANT BLOSSER was a young man with clear blue eyes and good shoulders. He also had a jaw suitable for hammering rocks.

He said, "I am sorry, Mr. Savage; I cannot let you examine that box."

Doc Savage glanced at two policemen who had come to stand close beside him.

"Why not?" he asked.

"Fingerprints," Lieutenant Blosser said, and looked at the box.

The box resembled the one which Doc Savage had constructed from cellophane and left on the figurative doorstep of Uncle Joe Morgan. This one, if anything, was a trifle smaller.

"Get a photographer in here," ordered Lieutenant Blosser. "Have him get pictures of that box. Detectives Grant and Mozen, you watch the box. We do not want this one disappearing."

"That is a good idea," Doc said. "And we might take a look at the body."

He started to where the man lay dead on the floor.

Lieutenant Blosser got in his way and said, "I am sorry."

Doc Savage studied him. "What do you mean?"

"You will please stay where you are," the officer said rather stiffly.

The bronze man hesitated. Then he drew out a billfold, opened it and presented a document. "You will find this to be a commission," he explained, "on the New York police force."

Blosser shook his head.

"We are wasting time," Doc said, a trifle impatiently. "There appears to have been a murder here. You will find that this commission bears the rank of inspector, which is above your own, and entitles me to overrule your orders. I regret doing so, but—"

Lieutenant Blosser became pale.

"It is not a license," he said, nodding at the commission.

"A license for what?"

"To commit crimes," Blosser said bluntly.

Doc Savage said nothing for a moment. Then he asked, "Have you any objection to my calling Commissioner Strance?"

The white tension on Lieutenant Blosser’s face increased.

"It would relieve me greatly if you would," he said. He held his lower lip in his teeth briefly. "As a matter of fact, I was going to do so myself. You see, Mr. Savage, you are in a rather peculiar position in this thing."

Doc looked at him. "Peculiar in what way?"

"We received a telephone tip—anonymous—to the effect that you were behind these invisible-box murders. Also, that Elmer Ivers was to be killed and that you would appear here this afternoon and commit the murder."

Doc Savage made, briefly, the small sound which was peculiar to him in moments of mental or physical stress, a trilling which seemed to come out of inaudibility and travel musically up and down a scale, then ebb away.

Blosser added, "We came here. Mr. Ivers ridiculed the whole idea. He said he had no enemies; that he did not even know you. But we remained anyway, concealed in the neighborhood. We saw you come; saw Ivers admit you. And then—" He shrugged.

"You say a telephone tip brought you here?" Doc Savage asked.

"Right."

"What time was it received?"

"About an hour ago."

"Was it after one o’clock?"

"Yes, the tip came after one o’clock," Blosser said.

COMMISSIONER STRANCE, acting head of the police department, was a blunt granite rock of a man who had few words and used them like bullets. He had come up from pounding a beat in Gravesend, and there had never been a question about his honesty. Nor his courage.

He said, "Hello, Savage. Too bad. Don’t like it."

A homicide-detail detective came in from the room where the body lay. He had a sheet of paper and an envelope, tinted bronze.

Strance read the paper with hard eyes. He handed it to Doc.

If the police come to you and you tell them anything, even tell them you know me, you will not live long.

Savage.

"Found on the body," the homicide man said.

"Yours?" Strance asked.

"Type of paper I use," Doc admitted.

"You write it?"

"No."

Commissioner Strance stared at him strangely but did not comment. Strance was a man of few words, of steel convictions. He was not a man inclined to lean over backward in being fair. He believed, instead, that it was the duty of the courts and juries to decide innocence or guilt.

A detective came in and reported, "We’ve gone over the boat with a microscope, almost. There’s nobody else aboard."

Doc Savage’s flake-gold eyes became intent. He did not say anything. He knew by now that he was in a serious predicament.

A fingerprint man came in from headquarters. He had a card on which were Doc Savage’s fingerprints.

They compared these prints with a latent print on the crystal of a wrist watch. The crystal was cracked.

"Identical," said the fingerprint man.

Lieutenant Blosser stood in front of Doc Savage. "Watch off the dead man’s wrist," he said. "There was evidently a struggle, and the assailant grasped Elmer Ivers wrist. The assailant left a thumbprint on the watch crystal. The print is yours!"

Doc said, "Mind letting me look at that watch?"

Blosser took a step forward to comply, but Commissioner Strance interrupted with one word.

"No!" Strance said.

In a voice which showed no emotion, Doc Savage asked, "Mind letting me look at the dead man?"

Blosser glanced at Strance.

"No," Strance said. "Clues. He’s clever. Might destroy."

Doc Savage showed some of the astonishment he felt. He had been working with the police for a long time; he had done them many favors, and he had, in turn, received favors from them.

Lieutenant Blosser evidently knew what was in the bronze man’s mind. He began speaking.

"I fully understand your high position, Mr. Savage," he said. "And believe me, I regret this as much as I possibly can. But you can see the position in which we are placed. We received an anonymous tip that Elmer Ivers was to be murdered by you. To tell the truth, we did not believe it. But we showed up on the scene anyway. And sure enough, you appeared, and Ivers was murdered. All the clues point to you."

Doc made no comment.

Lieutenant Blosser said, "Perhaps you think we are being unduly harsh with you. But let me remind you that several men have died under mysterious circumstances. We have been without clues. The death in each case puzzled our chemists." He swung to a medical examiner. "Saunders," he said, "of what did that man in the other room—Elmer Ivers—die?"

Saunders, a competent-looking man, said, "I cannot tell. I do believe that it is the same thing that killed those other men. A laboratory test will prove the point later."

Blosser looked at Doc Savage. "You see. This is the fifth man to die mysteriously. We cannot overlook this; and, much as we regret it, I am afraid—"

Commissioner Strance interjected a grunt.

"Too many words," he said. He turned to Doc. "You’re under arrest. Charge is murder!"

There was just one other development. It happened immediately. Commissioner Strance asked to have a look at the cellophane box which had been found near the murdered man.

Lieutenant Blosser looked satisfied with himself.

"The boxes found on the scene of the other murders have disappeared damned mysteriously," he announced. "So I took good care that this one wouldn’t."

"Where is it?" Strance demanded.

"I put it in a pillow case," Blosser said. "And two of my men have been watching it."

He sent for the two men. They came in, carrying the pillow case.

"Open it," Blosser ordered.

One of the men untied a shoestring which he had fastened about the open end of the pillow case, fashioning it into a sack. He stared inside—and became pale. The other detective also looked into the sack. His jaw dropped.

"What the hell’s the matter?" Strance barked.

The matter was that there was now no box inside the pillow case!

Chapter IV. CONVINCING BLOSSER

LIEUTENANT COLONEL ANDREW BLODGETT MONK MAYFAIR and Brigadier General Theodore Marley Ham Brooks were a deceptive pair. Each had, on necessary and urgent occasions in the past, risked his life to save the other. To listen to them associate with each other, no stranger would believe this possible. No one ever recalled Ham’s having said a pleasant word to or about Monk. And vice versa. The unpleasantness even extended to their two pets, Monk’s pig, Habeas Corpus, and Ham’s chimp, named Chemistry. They fought several times a day.

Monk slammed down the telephone in Doc Savage’s headquarters.

"They’ve got Doc in prison!" he said. "We’ve got to do something."

Perspiration had come out on Monk’s homely face.

Ham said, "That is ridiculous."

"It’s not so blamed ridiculous but what it has happened," Monk said. "You’ve been bragging for years around here that you had the brains of this gang, you overdressed shyster. So now you better deliver. Think of something."

Ham stared at pretty Jen Bridges.

Jen’s fingers were against her pale cheeks. "This is terrible. I caused it. I asked Mr. Savage to help my brother, and now—"

"We are still helping your brother. Please don’t worry," Ham said.

Monk was tempted to walk over and kick Ham in the ribs, and his expression showed how he felt. Monk resented Ham’s enjoying the good luck of having been left at headquarters to take care of a girl as attractive as Jen Bridges. Monk could detect signs of Ham’s having made the best of the opportunity.

Monk took two angry stamping turns around the room. Then he went to the radio.

"Renny," he said. "You there?"

A voice, a rumbling like something big in a deep hole, admitted that Renny Renwick was present at another radio transmitter.

"We got into the flypaper the first thing," Monk said. "A girl named Jen Bridges showed up here and said her brother, David, had been grabbed and hauled off by some men. Jen is an artist, and Doc had her draw the faces of the men who kidnapped her brother. Doc recognized one of them as Elmer Ivers, a well-known banker and businessman. Doc went to talk to Ivers. Ivers was murdered—one of the invisible-box things. Doc is accused of the crime. Framed!"

"Holy cow!" said big-fisted Renny. It was his favorite exclamation. He was silent a moment. Then, "You want to know if Uncle Joe Morgan was hooked in it?"

"That’s it."

"I don’t see how he could be," Renny said.

"He might have called somebody to set this trap for Doc."

Renny rumbled disgustedly. "Wait until I contact Long Tom," he said. "He’s riding the telephone line to Uncle Joe Morgan’s office."

The consultation with Long Tom, the electrical expert of Doc Savage’s group of five assistants, did not take long.

Renny reported, "Long Tom says Uncle Joe Morgan has not used the telephone since Doc left the place. Long Tom also says he has not used any other kind of device, radio or wire, to signal anyone. Long Tom has some kind of a supersensitive detector rigged up that tells him that."

Monk demanded, "What about you?"

"From where I am posted," said Renny, "I can see right into Uncle Joe Morgan’s office. He has not been out of sight. He has hardly been away from his desk. He just sits there and fiddles with his watch."

"How do you mean—fiddles with his watch?"

"Keeps taking it out, holding it in his hands, playing with it, then putting it back in his pocket. And taking it out again. Does that over and over. Acts nervous about the time."

"A man named Ted Parks was to come to see Uncle Joe Morgan at four o’clock."

Renny said, "Ted Parks is the only other man, besides Uncle Joe Morgan, who knows all those men who have died in the invisible-box mystery. That right?"

"That’s right," Monk agreed. "That’s why Doc wants to talk to Ted Parks. He’s mixed up in this mystery some way."

"Just what is the mystery?" Renny demanded.

Monk let the radio remain silent for a moment. "You guess," he said finally.

Renny snorted.

"Say, Renny," Monk said, "what about the lip reader you said you could get? Ham was going to hire a lip reader to sit in that office with you and watch Uncle Joe Morgan through a pair of powerful glasses. But you called Ham and said you already had one."

"The lip reader," said Renny, "has been on the job. But she hasn’t detected Uncle Joe saying anything. The old duffer doesn’t talk to himself, apparently, and he hasn’t had any visitors."

Monk looked interested.

"She?" he asked. "you mean your lip reader is a woman?"

"It’s Pat," Renny explained. "Pat has taken it up in her spare time. She’s pretty good, so I called her in."

Ham Brooks heard that and looked dumfounded. He came over and took the radio microphone away from Monk.

"Look here, Renny," Ham said. "Doc doesn’t want Pat mixed up in this. He gave me specific orders to that effect."

Renny did not answer. Instead, Patricia Savage’s voice came over the air.

"This is once," she said, "that I get in on one of these things at the beginning."

She sounded triumphant. She liked excitement.

Monk grunted and switched off the radio.

A BIT later, William Harper Johnny Littlejohn came in. He was the fifth member of the group of five assistants—six, including the obtrusive Pat. He was a very long, very thin man, a perambulating beanpole who wore a magnifying glass that passed for a monocle in his lapel. He was a famous archaeologist and geologist, and somehow he looked the part.

He used one of his words immediately.

"I’ll be superamalgamated," Johnny said. "I do—"

Monk pounced on him immediately. "None of those words of yours," he said. "I’m in no humor for them."

Johnny looked injured.

"No trace," he said, "of the individual or individuals who shot at Doc as he was leaving here to go to see Elmer Ivers."

WHEN they arrived at headquarters, Lieutenant Blosser was not brimming over with accommodation.

"This is a serious case," Blosser said. "However, considering that the prisoner is Doc Savage, I will let you talk to him."

"That’s fine of you," Monk said sarcastically. "After all Doc has done for the police."

Ham was also indignant. He popped an afternoon newspaper with his fist.

"Who gave this to the papers?" Ham demanded.

Lieutenant Blosser glanced at the newspaper. He had already read the item, and it had made him feel uneasy. The newspapers, never particularly a booster of Doc Savage, because the bronze man disliked publicity and was not at all co-operative in furnishing the press with sensational news, had not been kind in their stories of the bronze man’s arrest in connection with the invisible-box murders.

There were open hints that Doc Savage might not be the benefactor of mankind which he had hitherto appeared to be.

This particular newspaper commended the police on ignoring the bronze man’s special privileges.

"I’m not responsible for what the papers print," Blosser snapped.

They interviewed Doc Savage the way a common criminal would be interviewed, through a separating fence of steel mesh. Doc displayed no particular emotion, except that he smiled.

"I would like to know exactly what Uncle Joe Morgan did from the time I left him," he said.

Monk furnished a full report on that. Doc Savage listened without comment.

"Then all Uncle Joe seems to have done is sit at his desk and fiddle with his watch," he said, when the report ended.

Monk nodded. He was concerned and showed it.

"The thing doesn’t make heads or tails," he said. "What do you suggest we do next, Doc?"

"Get hold of Ted Parks if you can find him."

"If he doesn’t show up to talk to Uncle Joe at four o’clock, that will be a job." Monk glanced at his wrist watch. "It’s past four o’clock now, incidentally."

Doc Savage said, "Just keep stirring things up. Later, we may be able to launch a definite campaign."

As they filed out of the interviewing room, Monk muttered disconsolately, "The plain fact is, there’s nothing we can do, and Doc knows it."

Lieutenant Blosser met them outside. Commissioner Strance was with Blosser.

Strance said, "Blosser is your man. I’m assigning him to you."

Monk frowned. "What do you mean—assigning Blosser to us?"

"Just that."

Monk decided there was an unpleasant implication. He bristled. "You mean," he yelled, "that you suspect us!"

When Monk yelled, it was something. Cops dashed out of doors to see what was wrong. Growing more indignant, Monk took Commissioner Strance by the necktie.

"You knob-headed lug!" Monk said. "If you had any sense, you’d turn Doc loose and let him solve this thing. By locking him up, you’re working hand-in-glove with the murderer."

Commissioner Strance had a temper which did not arouse easily. But his neck got red.

"Blosser works with you!" he snapped.

"Watches us, you mean?" Monk bellowed.

"Frankly—yes," Strance said.

LIEUTENANT BLOSSER did not seem sensitive about his position in Doc Savage’s group of associates. He was not welcome, knew it and didn’t mind.

"You guys can outsmart me, I know that," he said. "But I would like to see you let me play along with you. After all, I’m not out to frame Doc Savage. I’m here to see that justice is done."

Ham saw the wisdom of that.

"I think we have the same aims," the dapper lawyer announced. "So there is no objection to your working with us."

Monk—he never agreed with Ham if he could possibly help it—let out a snort that was plainly expressive of his opinion.

They went to the vicinity of Uncle Joe Morgan’s office. They visited, in fact, the lookout across the street where Renny Renwick and Patricia Savage were keeping an eye on the frightened dealer in small-time stocks.

Colonel John Renny Renwick was a big man who was made very notable by the size of his fists. He had an enviable reputation as an engineer, and a voice which would serve as a foghorn.

Pat Savage was a cousin to the man of bronze. She had Doc’s metallic coloring—bronze skin, flake-gold eyes—and was extremely attractive. She seemed to radiate her liking for excitement.

Ham told Pat, "This is Lieutenant Blosser, assigned by the police department to assist us."

"The bloodhound of the Baskervilles," Monk corrected sourly.

The embarrassed Lieutenant Blosser was much impressed by Pat Savage.

Renny rumbled, "The old geezer hasn’t had any visitors yet. He keeps jumping up, sitting down, and fooling with his watch. This Ted Parks was supposed to come at four o’clock, Doc said. It’s way past four, now."

Ham took a look across the street at Uncle Joe Morgan’s office. He could see the benevolent-looking old gentleman stalking up and down; he seemed to be endeavoring to control himself.

"I think we might as well talk to him," he said. "I tell you what—Blosser, Monk and I will go over and put the conversational bee on him. Jen, you stay here with Pat."

"I’m worried about my brother," Jen Bridges protested. "Can’t we do—"

"We’re just as worried about Doc as you are about your brother," Pat told her. "This thing seems to be all hooked in together. When we get one straightened out, we’ll have them both."

Jen sighed, said, "I guess so," wearily, and sank in a chair.

WHEN Monk, Ham and Lieutenant Blosser got across the street, Uncle Joe Morgan at first would not admit them to his office. Blosser pounded on the door and shouted, "This is the police. Lieutenant Blosser of the homicide squad. Open up!" To which came a quavering demand to know how Uncle Joe could be sure they were police.

"Call headquarters and find out about me," Blosser snapped.

And evidently Uncle Joe did this, because he admitted them.

"Where is this Ted Parks?" Monk demanded, after they had identified themselves.

Uncle Joe became more pale, which didn’t seem possible, and flopped into the chair behind his desk like a fish hitting a dry bank.

He didn’t know. That was the essence of what he had to say, although he took many words, violent gestures, and tooth-chattering pauses to get the idea across.

"Just why are you so scared?" Monk demanded.

Uncle Joe Morgan blew up.

"I’m convinced I am going to be murdered!" he croaked. "The victims in the invisible-box things have all been acquaintances of mine."

Then an idea hit Uncle Joe. He looked as if he wanted to get on his knees, but he didn’t.

"Could . . . would some of you men, or a policeman, stay with me as a bodyguard?" he asked.

Lieutenant Blosser frowned and demanded, "What makes you so sure that your life is in danger?"

"I just know it," gasped Uncle Joe Morgan. "Only men I know are being killed by this thing."

Blosser was far from satisfied. "That note from Ted Parks, saying he would be here to see you at four and that you better be here and not notify the police—did that have anything to do with scaring you?"

Uncle Joe nodded violently. "It certainly did. Believe me, it did."

"Meaning—" Blosser’s eyes narrowed—"you think Ted Parks may be one of the instigators of this?"

Uncle Joe seemed to shudder from head to foot.

"Exactly," he said.

Then they drew lots to see who would remain with Uncle Joe. Ham lost, to his disgust, and was stuck with the job—despite the fact that he tried to get out of it by insisting his legal knowledge should be at working freeing, or trying to free, Doc Savage.

Uncle Joe seemed to have no definite reason for suspecting Ted Parks.

"All I can tell you about Parks," he said, "is that he used to live in an apartment on Fifty-fifth Street." He gave them the number.

"Did you tell Doc about that apartment?" Monk demanded.

"I forgot it," said Uncle Joe.

MONK and Lieutenant Blosser collected Long Tom, Renny, Pat and Johnny, as well as Jen Bridges, and lost no time in getting into cars and heading for the Fifty-fifth Street address. All seven of them rode in the same car, a limousine, and it was crowded. Blosser, who was in front, rolled down the window and demanded, "Say, just what do you know about this Ted Parks?"

Pretty Jen Bridges looked puzzled. "Who is Ted Parks? You keep referring to him, but nobody has told me who he is."

"He’s the one man besides Uncle Joe Morgan who knows all the men who have died mysteriously," Monk told her. "That’s all we have been able to dig up on him."

Big-fisted Renny rumbled, "Well, he’s a young doctor. We learned that much. He finished courses in this country and took advanced medicine in Europe before everybody started shooting at everybody else over there. After that, he dropped out of sight, reappeared in New York, was gone again, and then came back. The last time he came back, he had changed. He was thin, looked as if he had been very ill and was deeply sunburned."

"Tanned, you mean," Monk corrected. "Tropical suns, probably. Looked as if he’d had the fever, they said at a club or two to which he had belonged."

Lieutenant Blosser spoke up then.

Had he not spoken, someone might have noticed that Jen Bridges had settled back in her seat with tight hands and an ebbing of color from her face.

"Say, how—or when—did you learn of all this?" Blosser asked.

Monk snorted. "We started investigating this thing, three days ago. Doc got interested in the murders because they were so weird. We had nothing to go on. So we began checking on acquaintances of the dead men. We found that only two men seemed to know all the victims. The two, as I’ve told you, were Uncle Joe Morgan and Ted Parks. We were able to dig up quite a bit on Morgan—mostly that the old codger is interested in sailing, and goes away on long ocean cruises on his little boat. But about Ted Parks, we learned less. Parks is a clever fellow, and something of a figure of mystery."

"You mean," demanded Blosser, "that Parks has hidden his actions during the last year or two?"

"I don’t know whether he hid them," Monk said, "or was just a modest fellow. Anyway, nobody seems to know much about what Parks has been doing with his time."

Renny said, "Ham learned that at Harvard they considered young Parks a genius."

Monk sniffed.

"They consider Ham a genius at Harvard," said the homely chemist disgustedly. "They must be a dime a dozen up there."

THE apartment was on the third floor of a walk-up on Fifty-fifth Street, on the wrong side of Broadway. They got the manager to open the door for them. Lieutenant Blosser’s badge did that without much argument.

Lieutenant Blosser seemed to be feeling that there was more and more possibility of Doc Savage not being guilty. Monk, Pat and the others felt they were doing well, even if not making much progress.

But what they found in the apartment blew to bits everything they had accomplished.

First, nobody was home. Nobody alive, more exactly.

Secondly, the man dead on the floor had one hand outstretched, with a pencil in the hand, and the flyleaf of a book open under the pencil.

"Parks!" yelled Blosser. "They’ve killed him!"

Jen Bridges made a sound like the last dying note of a small siren and collapsed on the floor. As she went down, every joint in her body seemed to bend, like the joints in a carpenter’s rule.

Monk said, "It isn’t Parks. Parks is a younger man. Pat, see if Jen’s heart was all right."

Pat bent quickly over Jen Bridges.

The dead man on the floor was a toughened fellow of middle age, not vicious, but with calloused hands, a deeply weathered hide, and snaggled teeth. His clothing was fairly new but looked as if it had come out of a bargain basement. Pants and coat did not quite match, although both were blue.

Lieutenant Blosser stepped close to him, then looked around the room.

"This is another one of those invisible-box killings," he said. "Where’s the box?"

There was no box.

Pat straightened from examining Jen Bridges. "She is all right. She just fainted."

Monk swung forward, bent over to look at the pencil in the dead man’s hand and at the note on the floor under it.

Monk read—and turned white. Renny Renwick said afterward that Monk lost so much color, and had such a weird expression on his face, that he looked completely like a ghost.

The note:

Savage killed me because—

That was all. The man seemed to have died as he finished the word "because."

Lieutenant Blosser read it. He straightened, took a service revolver from a belt holster and held it without pointing at anyone in particular, but so that it menaced everyone.

"This convinces me," he said, "that Savage is as guilty as they come."

Chapter V. SLEEPER, MINER AND MONKEY

AT ten o’clock that night, it was still warm. The day had been hot, and the heat held on with unabating stuffiness. Heaviness of the warmth penetrated into the district attorney’s conference room, which was not air-conditioned. No one in the room was comfortable. The D. A. wiped his face frequently, and Lieutenant Blosser had put a handkerchief inside his collar. Commissioner Strance was red-faced in the heat. Doc Savage was without his necktie, but that was because of the custom of taking neckties off prisoners, so that they will have nothing with which to throttle themselves. There were no strings in his shoes, either. The others—Ham, Johnny, Long Tom, Renny, Pat, Jen Bridges and Uncle Joe Morgan—sat around in discomfort. Of the whole group, Monk was the only one who had removed his coat. Monk did not give a particular hoot about what people thought of his looks; he had long ago realized that nothing he could do would make him much more homely.

Ham Brooks made a statement.

"The whole thing is too pat," said the lawyer. "It’s a frame-up. Anybody with eyes can see that."

Commissioner Strance showed his teeth.

"Old stuff," he said; "claiming frame-up."

Ham colored indignantly.

The district attorney—his name was Einsflagen, and he had ambitions in the direction of the governorship—rapped the table sharply.

"I wish you would remember, Strance, that you are not dealing with an ordinary individual," he said. "Mr. Savage is a famous man. He is known all over the world. I can hardly believe this thing about him, and it may not be true. Therefore, he is deserving of every consideration."

Commissioner Strance showed his teeth again, unpleasantly.

"Crook is a crook," he said. "And murder is what electric chairs are for."

No one said anything for a while. Ham breathed heavily. He knew, better than any of the others probably, the gravity of the situation. There was already, Ham stood convinced, enough evidence against Doc Savage for even a mediocre district attorney to get a jury to convict him of murder.

Monk also was silent. He was thinking, remembering the body of the man who had died when the gun exploded in the corridor outside Doc’s skyscraper office.

Monk had done something about the body. He hadn’t told any of the others. But he wanted Doc Savage to know about it.

The bronze man and his aids, when they wished to communicate without being understood by strangers, ordinarily used an ancient Mayan dialect which they had learned in the course of an earlier adventure. The Mayan tongue, differing from the lingo spoken by the modern Mayans in Central America, could be understood by very few people in the civilized world other than themselves.

Monk began coughing and sputtering, apparently. That was the beauty of the Mayan lingo. You could use it, and still sound as if something was caught in your throat.

Monk said in Mayan, "I concealed the body of the man who was killed when his gun blew up. The others are keeping still about it; so that is one less killing they will try to hang on you."

Doc Savage indicated by a slight gesture that he understood. Monk took out a handkerchief and wiped his lips, then blew his nose.

District Attorney Einsflagen tapped his desk distractedly.

"A most unpleasant affair," he said. "The last victim has not been identified; the man found in this Ted Parks’ apartment is the one I am referring to. Neither have we been able to locate Parks."

Ham got to his feet. "Mr. District Attorney, I did not ask for this meeting in order to rehash the case, or discuss the progress being made toward its solution."

Einsflagen eyed him. "Why did you ask for the meeting?"

Ham took a deep breath.

"I demand," he said, "that you release Mr. Savage. The evidence against him is planted evidence, a fact that is obvious from the circumstantial nature of it."

DISTRICT ATTORNEY EINSFLAGEN was in a predicament and knew it. The bluntness of Ham Brooks’ demand did not surprise him. He respected the directness more than if Ham had tried to use oratory and persuasion. In Einsflagen’s opinion, oratory was only used on fools; and he resented people trying to talk him into things. He supposed Ham knew how he felt, and that was why Ham had been direct.

None of which changed the fact that Einsflagen could not afford to make a mistake. Doc Savage was prominent, influential, not a man to be wronged. Einsflagen felt that, if he made a mistake now, fat chance he stood of ever becoming governor. He turned slowly to face Doc Savage.

"Mr. Savage, this puts me in a spot," he said frankly. "So I am going to ask you something. I am going to ask you if, were you in my position and had a prisoner against whom there was the circumstantial evidence which is against you, what would you do? Before you answer, I want to point out that the evidence seems to indicate you are certainly guilty of two murders, and possibly four others. Realizing this, what is your answer? If you were in my shoes, what would you do?"

The bronze man’s response was prompt.

"The evidence indicates that I am guilty," he said. "That leaves you with no alternative but to hold me."

The color, and relief, slowly came back into Einsflagen’s eyes.

Doc Savage began speaking.

"Monk, Ham, and the rest of you—I want you to set your watches exactly with the clock here," he said. "I want all your timepieces to be together. Jen, you and Mr. Morgan please set your watches, also."

Uncle Joe said, "I do not understand this."

"Would you mind complying anyway?" Doc suggested.

The benevolent old gentleman smiled and took out his watch, a large turnip affair of dull-looking metal. He set the hands with the wired time-clock on the wall, as did the others.

Commissioner Strance and Lieutenant Blosser looked on in puzzled astonishment. The district attorney was blank.

Doc said, "Good. Now, here is what I want you to do."

He fixed his gaze on Renny.

"Renny, at exactly midnight, I want you to walk into the advertising office of the Daily Planet and insert an advertisement for a man who has slept three weeks at a stretch."

"A what?" demanded the astounded Renny.

"I want a man," said Doc Savage patiently, "who has slept not less than three weeks without waking up, and can prove it. Preferably the proof shall be medical testimony, although that is not absolutely essential."

He pondered a moment.

"We do not need to discriminate in this matter," he added, "so you can advertise for either a man or a woman. But they must have slept three weeks or more."

Renny swallowed.

"Holy cow!" he said.

Doc turned to Monk. "Monk, at exactly one o’clock, in the Morning World, I want you to insert an advertisement for a man who is a radium miner."

It was Monk’s turn to drop a jaw. "Any particular kind of a radium miner?"

"Just one who has engaged in the business within the last few years for a period of not less than one year," Doc said.

Monk swallowed. "O. K."

Patricia scratched her head and asked, "Don’t I get a hand in this?"

"You," Doc told her, "can take charge of the monkey hunt. I want the names and addresses of every person who had bought a monkey, or sold one, during the last six months."

"You mean just here in the city?"

"All over."

"Great grief!" Pat ejaculated.

"That will not be as much a job as you think," Doc said. "Monkeys are very scarce outside of zoos, circus organizations, and a few for organ grinders."

"If you want to know who bought monkeys recently, I’ll get the information," Pat said.

"That," Doc Savage told them, "is all."

LIEUTENANT BLOSSER started to leave the police station with them. Monk got in front of Blosser, beetled his eye brows and said, "Don’t we ever get a vacation from you?"

"I have orders to continue to string along with you," Blosser said.

"Legally," Ham put in, "you can’t do that."

"Keep out of this, shyster," Monk growled at Ham. To Blosser, he said, "Physically, you can’t do it either, and I’m the guy who will demonstrate."

Lieutenant Blosser, who had shown few signs of being scared of anything, returned Monk’s scowl with enthusiasm. "You lay a hand on me," he told Monk, "and you will learn two or three things in a hurry."

"Come on," Renny rumbled impatiently. "Holy cow! We get tired enough of Monk and Ham squabbling. Do we have to put up with a new addition to it?"

Monk stalked to their car. His feelings were not improved toward Lieutenant Blosser when he discovered that Ham had made use of the diversion to grab the seat next to pretty Jen Bridges, a location Monk had earmarked for himself.

They drove uptown, all of them in one sedan, except Renny, Johnny and Uncle Joe Morgan, who followed in another machine.

Pat was growing more puzzled.

She remarked, "A radium miner, a man who has slept three weeks and people who have bought monkeys."

Jen Bridges wrinkled her forehead. "I do not understand Mr. Savage making such strange requests."

Ham said, "When you’re around Doc, you frequently bump into things you don’t understand."

Pat was lost in thought for a while longer. Then she did an unexpected thing. She leaned back, a light of relief overspread her attractive face, and she laughed.

When the others stared at her, startled, Pat said, "Brothers, get rid of those long faces. Doc has got the whole thing figured out right now, I’m willing to bet you."

Jen Bridges frowned. "What makes you think that?"

"When Doc starts doing things nobody can understand," Pat assured her, "he is really making progress."

They drove into the garage at headquarters. The garage was situated in the basement of the great building. It was entirely private, its doors actuated by radio control, and was served by a private elevator.

The car containing Uncle Joe Morgan pulled into the garage behind them.

Renny told Monk in an aside, a bit later, "That old Morgan codger worries me. I think he’s the most scared man I ever saw. We ought to give him something—a sedative or a hypnotic or something."

"A night’s sleep might help him."

Renny shook his head. "The only way he’ll get to sleep is for someone to hit him with a sledge hammer."

Chapter VI. DANGER FOR DAVID

THE sun came up the following morning, throwing its light into the eighty-sixth floor windows of the midtown building. The sunlight splashed over Monk as he read a half-page newspaper advertisement that began:

RADIUM MINER WANTED

"My ad sure got a display," he said. "Renny, how did yours come out?"

Big-fisted Renny Renwick was studying another paper. He rumbled disgustedly.

"Holy cow! They seem to think it’s some kind of a gag—our wanting a man who has slept three weeks and can prove it by a doctor’s testimony. Here’s a story in a box on the front page about it. Couple of other papers are carrying the story, too."

"That’s good," Monk said.

"It sounds goofy," Renny complained.

There was an interruption in the shape of an uproar—sound of things upsetting, angry squeals.

"Who’s got hold of my hog?" Monk yelled, leaping to his feet.

Habeas Corpus, the pig, shot out of the library, sounding like a small locomotive with exhaust stacks open and whistle going at every other jump. Attached to one of his legs was a string and a particularly hideous photograph of Monk.

Monk captured his pig and untied the photograph.

"Who did that?" he bellowed. "Where’s that Ham Brooks?"

"Oh, shut up about Ham!" rumbled big-fisted Renny. "He isn’t even here. He is out having breakfast with Jen Bridges."

That didn’t improve Monk’s temper. He scowled. "The hog didn’t just get tangled up in that cord and picture," he said. "There was a knot in the cord."

Renny looked at the photograph of Monk. He chuckled.

"I can understand it’s scaring the hog," he said.

Monk subsided into an indignant silence.

It could not have been more than five minutes later when the telephone rang. Monk picked up the receiver. It was a voice he had never heard before.

"Put Doc Savage on here," said the telephone voice.

"Doc," said Monk gloomily, "is in jail. Don’t you read the newspapers?"

The voice was silent a few moments.

Then: "Just the advertisements," it said.

"You mean those advertisements in the newspaper?" Monk was interested.

"Yes."

"Which one are you?" Monk demanded. "The radium miner or the man who has slept three weeks or longer?"

"I’m Ted Parks," the voice said.

"Oh, I thought you might be somebody—who?" Monk bolted upright. "Ted Parks? Where are you?"

The voice which had identified itself as belonging to Ted Parks was silent a while.

"I’m where I have been hiding out," it said finally. "Listen, since you fellows advertised for a radium miner and a man who has slept three weeks, it’s obvious you understand what is behind the murders they are calling the invisible-box killings. You are wise, aren’t you?"

"Oh, sure," said Monk, who did not have the slightest idea what connection a radium miner and a sleeper could possibly have with the invisible boxes. "That is, there are some points we don’t know. We would like to have them cleared up. Can you do that for us?"

Again the pause.

"Would you care to drop around and talk to me?" asked the voice.

Trying not to seem too eager, Monk said, "I suppose we could. But it might be better if you came here."

"I can’t come there."

"Why not?"

"I might not be alive when I get there."

"Well, we can come to see you, then."

"You must promise not to tip off the police."

Monk said, "That won’t be so easy. There’s a cop named Lieutenant Blosser who has fastened himself on us, and I don’t know whether we can give him the slip."

"You’ve got to."

Monk considered. "All right, we’ll do it some way."

"When you slip this cop," said the voice, "come to 346 Westwood Road."

That was all the voice said.

MONK and Renny Renwick wore innocent expressions when Lieutenant Blosser, Pat, Ham and Jen Bridges returned to the reception room.

"We left Long Tom and Johnny finishing their breakfast downstairs," Blosser explained. "There been any developments?"

"All’s quiet in the dawn," Monk said. He yawned and patted his stomach. "Renny, what do you say we turn it over to them and go down get a bite to eat?"

Renny tried to look hungry. "Suits me."

They arose, sauntered to the elevator and rode it down to the street level. They headed on a run for the restaurant in the building, flung through the doors, dashed for Johnny and Long Tom.

"Come on!" Monk barked. "We’ve got a line on this Ted Parks!"

"I’ll be superamalgamated!" gasped Johnny.

They dashed outside and scrambled into a taxicab, after Renny warned, "There’s a checker-light in the laboratory that lights up when anybody is in the garage. We better not try using one of our own cars."

Renny rumbled at the cab driver, "346 Westwood Road."

"Where’n heck’s that?" asked the cabby.

They got out and went hunting a street directory on the newsstand. "I wish I had Doc’s memory for streets," Monk complained. They found Westwood Road to be in the Bronx.

The cab ran over to the elevated highway and shot north past the piers that were whiskered with steamship masts and colored funnels. There was very little outbound traffic, and the speedometer wavered around sixty.

Monk chuckled. "We worked that slick. Blosser is sidetracked there at headquarters. And the two girls are safe there, too. Ham can take care of them." He burst out in laughter. "Ham is going to miss this. He won’t like that."

They turned off on Westwood Road where it angled down sharply toward the river. It was a decrepit district—old shacks and, close to the river, the remains of an amusement enterprise which had been abandoned.

The place was a cross between an amusement park and a night club, not extensive enough for one and too large for the other. The fence around it had been coated with stucco once, but most of this had scabbed off. The place seemed to be No. 346.

They paid off the cab.

"Go back three blocks and wait for us," Monk told the driver.

That aroused the suspicions of the driver. They watched him drive back the three blocks, hesitate, then go on, increasing his speed. The cab disappeared.

Renny mumbled disgustedly, decided, "Oh, well, we can get another cab."

They decided that a convenient alley was the best approach to the ruin they were to investigate.

Twenty yards inside the alley, a young man stepped out before them. He stood there. He seemed to think they should recognize him.

"Well," he said finally, "haven’t you seen my picture, or got my description?"

"Ted Parks?" Monk asked.

"That’s right."

THE young man was tall, muscular in a slab-sided way. He had dark hair, a somewhat small mouth, eyes which were sunken and hard to read behind large spectacles.

"I figured you would come down this alley," he said. "So I waited here. I had to head you off."

Monk eyed him. "You had to head us off?"

"Exactly."

"Why?"

The young man jerked a thumb over his shoulder. "They found me," he said. "That is, they found where I was hiding. But I saw them coming. They’re searching the place, now. There are four of them."

"Who are they?"

"Do you know a man named David Bridges?"

"Is that the one," asked Monk, "who has a sister named Jen?"

"That’s him."

"We’ve been hearing of him. We haven’t met him. He was supposed to be seized last night by some men and carried off. His sister came to us for help."

The tall, dark, intent-looking young man seemed astonished. Then a grim smile twisted his lips. "That’s good," he said. "The sister took you in."

Renny blocked out his big fists. "You mean that girl has been lying to us?"

"That girl is one of the murderers," the young man said. "I don’t know whether she has lied to you, because I’m not aware what she has told you."

Renny demanded, "Why should she lie to us?"

The other snorted. "To get next to you, of course! So she could be with you, find out your moves, and tip off her brother so you couldn’t catch him."

"Her brother is behind this?"

"Sure!" The young man jerked his head toward the dilapidated ruin near the river. "He’s in there, now. He’s one of the four men looking for me."

"There’s only four men in there, now?"

"Yes."

"Let’s take them," Renny rumbled.

The young man seemed apprehensive. "They’re tough guys. They may try to use that invisible-box death on you. I don’t know what it is, but they may try it."

"Come on!" Monk said.

Johnny Littlejohn held up a hand. "Wait a minute. Parks, suppose you sketch this thing for us? Make it brief. We want to know what is going on."

The young man nodded. "Here it is in a nutshell. Four men have died mysteriously—or rather, six, now. I see by the morning newspaper that an unidentified man was found in my apartment, and my friend Elmer Ivers died yesterday afternoon. I know all those men except the unidentified one. As far as I can learn, I am the only one who has known them all. So I got scared, began investigating, and immediately an attempt was made to kill me. So I hid out."

"Why didn’t you go to the police?"

"I was afraid they would try to frame something on me."

"That’s kind of a thin excuse," Johnny suggested.

"I don’t give a damn how thin it is," said the other. "It’s the truth."

Johnny was using small words, which indicated that he was excited.

"Uncle Joe Morgan—do you know him?" he asked.

"Sure. A harmless old codger. He knows all of the men who have died, too. But I discounted him. He isn’t the kind of an old duffer who would be mixed up in a thing like this."

Johnny was becoming suspicious.

"That isn’t telling us much," he said.

"I don’t know much."

"Have you told us all you know?"

"Yes."

Johnny took a grim step forward. "When you telephoned Monk, you said you did so because of the advertisements in the newspapers for a radium miner and for a man who had slept three weeks."

The young man backed a pace. His face twisted. Then he lifted his voice.

"Take them, fellows!" he called.

Men began coming out of adjacent doors and windows, men with guns and unpleasant expressions!

"IS there just these four, Nick?" one of the armed men asked.

"That’s all," said the young man.

Johnny’s expression was assured, calm, as if nothing had happened. It would have done credit to Doc Savage.

"I’ll be superamalgamated! You are not Ted Parks," he remarked.

"Naturally not," said the young man. "You walked right into it, didn’t you?"

Monk said, "And walked right out again!" and kicked the arm which the young man was using to draw a gun. The arm broke in at least two places.

One of the gunmen shot Monk in the chest. Monk walked over to him—rather, he made it in one great jump—and grabbed hold of him. As soon as Monk took hold, the man began screaming.

Monk had a little trick or two which he liked to demonstrate to friends, one of these being to take a silver half dollar between thumb and forefinger and bend it until the edges touched. The man’s screaming was more horrible than loud.

Another man bellowed, "A bulletproof vest! They’re wearing—" He didn’t finish, because Renny got him.

Johnny tangled his long, bony frame around two others.

Long Tom, the electrical wizard, paused to drag out a thing that could have been an iron goose egg, but wasn’t. He dropped this; and it popped like a firecracker, throwing out particularly vile, yellow vapor.

"Tear gas!" a voice squalled.

It was a natural, if wrong, conclusion. The stuff was not tear gas. Forms of tear gas could be defeated by a mask. This stuff was more sinister. It worked through the skin pores. Monk was very proud of it. He had worked it out in co-operation with Doc Savage.

Best point of the gas was the method Doc Savage and his aids used in immunizing themselves. They did it by using small quantities of the gas daily on themselves until their systems built up what is sometimes called a tolerance for the stuff. They had done this over a long period of time.

Strong quantities of the gas would make them unconscious. But small amounts, such as exuded from grenades, made them only a little dizzy.

Two minutes later, Long Tom calmly stepped up to the last dazed would-be attacker and knocked him down.

"That," announced the puny-looking electrical wizard, "is that."

IT wasn’t—quite. Long Tom hadn’t taken into account the presence of two other attackers, well clear of the gas. These men were armed with automatic rifles, and they had kept under cover. A kind of reserve troop, as it were.

They showed themselves and their guns.

"Get your hands up!" ordered one man.

Monk and the others stared in astonishment. They had presumed all forces were in the attack. These new entries had caught them by surprise.

"Guess we’ll have to blast ‘em, Jake," said one rifleman. "They’ve got bulletproof vests on; so shoot them in their heads."

Monk hastily shot his hands above his shoulders. Renny, Johnny and Long Tom did likewise. They were trapped!

The two automatic-riflemen came close, but not near enough to get into the gas.

"For some reason or other," one of them remarked, "that gas got our boys, but didn’t affect these guys."

Monk got an idea. He registered worry.

"Look here, let us step out of this stuff!" he said pleadingly. "If we stand in it, the gas will get us."

The riflemen took the bait.

"Just stand in it, then," one said.

Monk had expected that. He let his jaw sag and his eyes roll, trying to look weak. He sank to his knees. He groaned. He slumped forward on his face.

Renny, Long Tom and Johnny followed the homely chemist’s example.

"I’ll be danged," said one of the riflemen. "It did get them, at that."

He pulled out a whistle and blew it. It was a police whistle, so it had a natural sound after the shooting.

The police whistle accounted for the misfortune which befell the police patrolman who happened to have the neighborhood beat. The officer arrived in a hurry, gun out, demanding to know what was going on.

"Homicide detail," said one of the riflemen, pointing at his own chest with a thumb. "Look here, will you hold my gun a minute? I want to search those fellows."

He walked toward the patrolman holding out his rifle, butt first, and got close enough to the officer to bump him forcibly between the eyes with the metal-plated walnut. The officer collapsed, not dead, but disinterested.

A truck appeared. It was a large truck with a van body. Obviously, summoning it was the purpose for which the police whistle had been blown.

By that time, the wind had drifted the gas away from the recumbent forms in the alley.

"Load them in the truck," ordered a rifleman. "All of them. We’ve got to get out of here."

"What about the cop?"

"Oh, let him lay!"

"He saw us," said the other rifleman.

"That’s right. Better bring him along, too. We’ll get rid of him when we get rid of the rest of them."

THE truck was powerful and noisy. It rumbled northward at a rapid clip, following streets which trucks usually followed. They were not allowed on the boulevards or highways.

One of the riflemen produced a rope from a box and began cutting it into lengths.

"We’ve got to tie up Savage’s men," he said. "Here, help me divide this rope up so it’ll go around."

The other rifleman helped him. There were three additional men who had been in the truck when it came. They made, including the unconscious victims and prisoners, a crowd.

The second rifleman said: "Jake."

"Yes," replied his companion.

"When they were talking—did you hear them say something about a man, or somebody, named David Bridges?"

"Yes."

"Who can David Bridges be?"

"He’s a brother of a girl named Jen Bridges, didn’t they say?"

"Who the hell is Jen Bridges?"

"There you’ve got me."

They finished cutting the rope.

"What do we do with these guys, now? Knock them off?" asked one of the trio who had been in the truck.

"Not until we catch Ted Parks, or find out where he is," said a rifleman—not the one named Jake. "Them’s orders. Find Ted Parks, then croak these fellows and frame it on Parks. Then see that Parks commits suicide before he can spill what he knows to the police." The man chuckled. "Nice, eh?"

They began tying the prisoners. A man took hold of Monk’s ankles. Monk became active.

The truck suddenly filled with uproar! But it was a sad kind of an affair, taken generally. Monk and the others had underestimated the effects of the gas, or the good qualities of the tolerance they had developed to the stuff. The gas had not weakened them as much as it had slowed their ability to react.

The upshot of it was that Renny and Johnny were almost immediately knocked senseless with blows from rifle stocks. And Johnny was pinned helplessly under two bodies.

Monk fared better. Monk was a fighter by nature and instinct. It was the thing he liked best to do.

So he got out of the truck. He literally burst down the tailboard, and piled out to the highway. He did this as a last resort, after he saw what had happened to Renny, Long Tom and Johnny, and understood the same thing would soon occur to him.

The truck was going all of forty miles an hour. Miraculously un-killed, Monk rolled like a ball. He managed somehow to direct his wild tumble so that he ended up near the curbing, on his feet, and running.

He ran somewhat after the fashion of a man with one leg off at the knee. But he made time. And the erratic course he took caused three rifle slugs, and all the bullets from at least one revolver, to miss him.

He got into bushes. He ran.

TEN minutes afterward, Monk stumbled into a small neighborhood grocery. It was a district of small homes and few mercantile establishments.

"Telephone!" Monk gasped.

They stared at Monk, pop-eyed. There was now a little hide left on Monk’s hands and features, but not much. His looks were not improved.

He found the telephone for himself and dialed headquarters. Ham answered.

"Ham, please don’t give me an argument," Monk said. "Listen to this: Ted Parks is in danger and is to be framed for those invisible-box deaths. Jen Bridges is deceiving us. She may not even have a brother named David Bridges. The girl is a crook."

"You’re crazy!" Ham said.

"Listen—Renny, Long Tom and Johnny are in a truck. Prisoners! Headed for I-don’t-know-where. They are to be killed. The killing framed on Ted Parks."

Ham was incredulous. "What is this you’re telling me? Where the devil are you? You are crazy, aren’t you?"

"We walked into a trap," Monk said. "Get up here as soon as you can. The truck is headed north. We may be able to spot it. I’ll contact the State troopers and have them start watching for it."

"Where are you?" Ham demanded.

Monk turned around, looked at the storekeeper, and asked, "Where am I?"

The man told him, stuttering somewhat.

Monk relayed the information to Ham.

Then the rifleman named Jake and one of the men from the truck came into the store behind guns! They wore masks made out of handkerchiefs. They fired a few bullets into the ceiling.

Monk tried to run, but he was weak, exhausted, his lungs on fire and his legs rubber. They beat him down, hammered him some more, then hauled him outside. Jake paused long enough to pull the telephone loose from its wires, as if it were fruit on a vine, and hurl it at the gape-mouthed storekeeper.

Chapter VII. ONE MAN LOOSE

HAM BROOKS, in the headquarters reception room downtown, heard some of the uproar in the distant store. He also identified the noise of the telephone being ripped from its wiring. He was not cheered.

He turned a pale color which would have caused Monk to razz him unmercifully, had Monk seen it. Ham thought a lot of Monk, actually.

He upset a chair getting from behind the desk.

"Monk and the others—they got a call from a fake Ted Parks and went to see him. It was a trap." He ran to a corner for his sword cane, an innocent-looking piece of foppery. It was a black cane, the blade of Damascus steel, tipped with chemicals which caused unconsciousness.

Lieutenant Blosser bounded to his feet.

Ham told him, "You stay here. Take care of Miss Bridges and Mr. Morgan."

"I go with you," Blosser said grimly.

Pat had disappeared into the laboratory. She came out with a case of equipment, one of the small bronze metal boxes which they habitually used as containers.

"We’ll all go," she said. "What’s wrong with that?"

There was plenty wrong with it, but Ham didn’t believe there was time to argue. He remembered Monk had said pretty Jen Bridges was a fake. Ham could hardly believe that. He wanted time to think before he committed himself to a decision.

"Come on, then," he said impatiently.

They piled—Ham, Blosser, Pat, Uncle Joe Morgan and Jen Bridges—into the special elevator to the basement garage. They selected a car. Ham did the choosing. He picked the machine they called "the tank."

"Get in!" he barked. "Hurry up!"

Outwardly the car resembled any six- or seven-year-old rich man’s limousine. The interior was not much different. But the body was armor plate, the windows the best process bulletproof glass, the body gas-tight. It could knock down a stone wall, or at least come as near doing so as an army tank.

Ham opened the radio-controlled doors while he was starting the engine. The garage doors slid apart as noiselessly as big lips.

They drove out into the street.

What happened then was not excusable because it was unexpected. Ham was looking for trouble. He got it. Violently!

A truck in front of them was big. It had good brakes and it stopped on a dime, almost literally. At least Ham jammed on the hydraulic brakes full force and barely escaped ramming the truck, which had a huge box car of a body.

There were other cars, one on each side. One a coupé, the other a coach, and looking entirely harmless. Too late, Ham realized their looks were deceiving.

He realized this when the truck pulled ahead a few feet, and Ham took his foot off the brake, thinking traffic had cleared and they were going on.

The back end of the truck body dropped down from the top. It formed a kind of ramp.

Ham was astounded.

Another car, a big and heavy one, hit him a hard blow from behind. In the fractions of seconds during which Ham could not get his amazed foot back on the brake, their car was knocked up the ramp and into the truck body.

Like a sheep being shoved into a box.

The thought in Ham’s brain was: "This is crazy! I’ve seen it in the funny papers! They’ve done it in movies! And it happened to us once before!"

But there they were.

LIEUTENANT BLOSSER grabbed the door handle.

"Stay in here!" Ham yelled at him.

Blosser was in the back seat. And he did not know that the car was a fortress, as hard to crack as a good safe. So he paid no attention to Ham’s advice. Blosser piled out.

The drop-leaf door of the truck was closing. Evidently, there was an arrangement of pulleys and lines. Blosser took a run, jump, a hard fall, and hit the pavement.

His police revolver was in his hand. One of the cars, the one that had bumped them, was just backing away. Blosser lifted his weapon with the idea of shooting the car full of holes. He did get one bullet into the windshield; then the machine was jumping at him like a great steel animal.

Blosser dodged the car partially, enough so that he was only knocked head over heels instead of being crushed to death. He lost his revolver.

He got the gun again in, it seemed to him, no more than a second. It must have been longer. Because the car was gone, and the truck itself was lumbering around the corner.

Lieutenant Blosser’s revolver held five cartridges, and he transferred the lead from these to the back of the big truck. There were no results. Except that the sidewalks cleared magically.

"Police!" Blosser howled. "Police!"

There was a police call box not six feet from him, but he was as excited as a citizen. He never even saw the call box. He tore down the street after the manner of a wild man, loading his gun as he went. All this got him was a briefly tantalizing glimpse of the truck disappearing in the distant traffic.

"Whew!"
gasped Blosser.

He tried to commandeer a cab, but the first two were strangely empty, and the driver of the third—he looked as American as the Bronx—was strangely unable to understand English. The fourth cab was piloted by a more venturesome character.

But, by then, it was too late. After Lieutenant Blosser had charged the cab around several blocks with the horn blowing steadily, he came to his senses enough to realize that the thing to do was to call the police.

It embarrassed him to remember how often he had given ordinary citizens hell for delaying less time than this in notifying the police when a crime had been committed.

Reaction had gripped Blosser, by now. He was both nervous and enraged.

He found a telephone and shook until he had to brace his elbows against the wall while he was notifying the radio bureau, then Commissioner Strance, then District Attorney Einsflagen, of developments.

"You had better come down to headquarters after the district men get there," Commissioner Strance told him. "The D. A. and you and I will have another talk about Doc Savage."

Chapter VIII. ACTION IN BRONZE

DISTRICT ATTORNEY EINSFLAGEN wanted very badly to be governor. He’d gotten the ambition when he was a kid who had to deliver papers after school to pay for his own clothes, and it had never left him. Practically everything he did was aimed toward that goal. His speaking, for instance. He had practiced public speaking endlessly, because he figured you had to be good at that to be governor. Whenever the chance presented, he was inclined to launch into elaborate rhetoric.

He was making a speech, now.

It hadn’t started out as a speech. The platform delivery had just intruded.

In sum and substance, he was taking fifteen minutes to tell Doc Savage that he was filled with respect for the bronze man’s mental equipment and that, therefore, things which Doc Savage did were frequently not what they seemed on the surface.

Take, for instance, said Einsflagen, the matter of the bronze man’s interest in contacting a man who had slept three weeks, a radium miner, and people who had dealt in monkeys recently. There was an example, Einsflagen suggested. Three things, all three bizarre, all three bearing no apparent relation to each other. That was an example of how Doc Savage’s brain worked. All three things—radium miner, sleeper, monkeys—were doubtless very important, but it befuddled an ordinary brain to try to see what connection they had with the matter in hand.

All of the speech-making led to a point.

This point was that the D. A. did not believe the seizing of Ham and the others was genuine, or the disappearance of Monk and his party, either.

"In other words," said Einsflagen, "your associates felt the necessity of doing one of two things: Either disappearing, or getting rid of Officer Blosser so they would be unhampered. We do not know which the motive is, I will admit."

For once, Doc Savage’s self-control slipped. He stared at them unbelievingly.

"You do not believe my men, and Miss Savage and Miss Bridges, are in danger right now? Perhaps dead?"

Einsflagen showed his teeth in what was no smile.

"We are not completely gullible," he said.

Doc Savage continued to stare at him.

"What are you going to do about this?" he asked tensely.

"We are going to order your men arrested on sight," said Einsflagen. "And we are going to presume that they are not in danger, have not been kidnapped, and that they are in a position to know more about this than they will, or have, admitted."

Doc Savage made his trilling briefly. It had biting, fierce quality.

He said, "I have been a fairly satisfactory prisoner thus far, I hope?"

The district attorney nodded. "I understand you have." He turned to Commissioner Strance. "He has, hasn’t he?"

Strance shrugged.

"Smart. Naturally, he’s model. Doesn’t mean a thing."

Doc Savage came to his feet grimly.

"From now on," he said, "you can expect something else."

THEY stood a guard outside the door of his cell for that. The guard was a burly cop who didn’t like people who enjoyed privileges. They must have picked him for that reason and told him Doc was ex-privileged.

Commissioner Strance did the guard placing. He did it at the urgent request of District Attorney Einsflagen. Strance himself was becoming a little dubious.

"I don’t know but what there might be a mistake here," Commissioner Strance told Doc. "But I’m not sure. As soon as I decide you might be innocent, I’ll do something about it."

"That," Doc told him grimly, "might be too late."

"Now might be too soon."

Commissioner Strance went away.

The guard looked in through the bars at Doc Savage.

"Let’s not have any trouble out of you," he said, not unpleasantly, but firmly.

The cell was one of a battery, a line of them opening on to a second-floor catwalk of steel. Second-tier catwalk would probably be a more apt description. At any rate, the doors all locked from a common bar, controlled by a time clock. The cells opened at a certain hour for breakfast, another for exercise hour, and so on. The rest of the time, it was controlled by a time clock, and nothing but a master key in the hands of the head jailer would open the doors.

It was almost exactly like a penitentiary, except that there was no enforced labor. No labor of any kind. And the prisoners wore their own clothes, minus the usual deletions of neckties, belts and shoestrings.

Word went through the jail that Doc Savage was in the place. It had a rather queer effect. Ordinarily, there could reasonably have been expected a demonstration of some kind. Instead, there was a complete silence. An appallingly complete silence.

It was as if a hawk had appeared over a flock of rather evil birds.

"Cigarette?" Doc asked his guard.

The guard had a red face and little knowledge of Doc Savage, or he would have known the bronze man never smoked.

Doc took the cigarette. He retired to the back of his cell. He did not smoke the cigarette. Instead, he burned a few yarns twisted from his blanket to make the odor and some smoke, but not enough smoke that anyone would notice it was wool burning, not tobacco.

The rest of the time he spent tampering with the cigarette. He crushed one of his shirt pocket buttons and inserted the powder in the cigarette.

The stuff was a chemical intended to be administered through the mouth, but it had the property of also being effective if smoked, like opium.

He let some time pass.

"Cigarette again?" he asked the guard.

The guard grunted and extended the package. Doc had a little trouble getting a cigarette out. He took the package in his own hands for a moment.

During the instant when he had control of the cigarette package, he was fortunate. He managed to get his doped cigarette into the package, substituting for one he took. He returned the pack to the owner.

He smoked the cigarette he took this time. He sat close to the cell door, smoked it and blew the smoke out through the bars, so that it would tantalize the guard.

It was done subtly and casually, and the guard fell for it. He reached into his pack, pulled out the handiest cigarette, which was the doctored one that had just been planted, and lighted it. He smoked luxuriously.

Doc allowed the proper time to pass. The guard was now glassy-eyed, rather rigid.

Doc said: "Guard."

The man did not answer.

Doc said, "Guard, go to the end of the stairs. Go down the stairs. There is a small automatic fire-alarm thermostat at the foot of the stairs. Strike a match and hold it against the fire alarm. When the bells begin to ring, pull the lever which unlocks all the cell doors."

The bronze man watched the guard walk away. He held his breath. The drug was a result of experiments with hypnotism and artificial aids toward inducing it. It was quite effective, but only briefly, in reducing the victim to a state where he would do anything anybody told him. But he would be in that condition less than five minutes, after which he would drop off in a sound slumber. So the drug, except for such uses as this, was quite useless.

(Following the usual policy of Doc Savage magazine, the actual chemical formulae used by Doc are not revealed, for the reason that such information in the wrong hands could do a great deal of harm. Furthermore, many of the chemical concoctions, improperly used, would possibly have fatal results.)

The guard struck the match. The substance between the electrodes of the alarm points—or a thermostat, if it was that type—did what it was supposed to do.

The fire-alarm bell cut loose.

For the sake of safety for the prisoners, the prison, a modern one, had been designed so that the cells could be quickly unlocked in case of fire without waiting for the master key.

The guard pulled the unlocking lever. There was a rattling. Doc immediately shoved open the door of his cell.

It was a tribute to the criminal world’s fear of the bronze man that no one tried to leave any of the other cells.

Doc ran along the catwalk; his feet took the steps in a machine-gun hammering, and he threw the lever back in position to lock the cells again.

The guard was weaving on his feet. "Wake up!" Doc told him. "When the guards come, yell that you are sick! Yell it loud."

The bronze man then went over to the only possible spot of concealment, a point not at all close to the flat steel door that led to freedom.

There was a concerted rush in answer to the fire alarm. Those who came bore fire extinguishers and guns. They shoved the door open, and those with guns came in first.

The guard did his act well.

"I’m sick!" he bellowed. "I’m sick, sick!"

And then he fell on his face.

Doc ran for the door when that happened. He had taken off his shoes because the strings were missing and they would have flown off anyway. He went on tiptoes, without much noise, as far as the door, where he was seen.

Men accustomed to routine require a little time to react to something new. A prison guard’s job is very dull routine. So Doc got fifty feet of flying start.

He reached another door just as more men came through with fire equipment.

"The fire may be there!" he told them. He pointed to help them out.

Doc was a man who believed in avoiding lies if possible. The fire might be in there, of course. Probably it wasn’t.

Anyway, it got him through that door, which was the last locked one. He put on speed. He was being fortunate. He had not expected it to click off as it had, like teeth of two matched gears fitting together. Tomorrow there would, he suspected, be a session of carpet-standing for those responsible for his uninterrupted flight.

He knew the layout of the building, now. He broke a window which admitted to an iron fire escape. This, in turn, deposited him in an alley, and it emptied him out on a street. He kept running. He was barefooted, tieless, hatless. Men do not go around in that condition on New York streets. Not as fast as they could run.

Eventually, he piled into a taxicab which was standing at the curb, motor running, but minus driver. He drove the machine away.

It was car theft, but he was not in the mood to worry about that. For one of the few times in his life, he was angry.

Chapter IX. TRAILS

A DEBONAIR, if big, old gentleman with a thorn cane walked out of a subdued apartment house on upper Madison Avenue. His hair was white; it looked like a fall of snow on his head. His skin was very light, rather white, in fact. His mustache was the ample type commonly known as a soup strainer, and his Vandyke was clipped like a French poodle.

He twirled his cane, whistled merrily, and asked a policeman where he might find Monsieur Piquen’s of Paris, Fifth Avenue Branch. The cop didn’t know.

What was more important, the officer didn’t know that the old gentleman was Doc Savage in a disguise. This was particularly good, because it happened that the policeman was one who knew Doc quite well by sight.

The exclusive club patronized by Ham Brooks, the lawyer, was in the neighborhood. Doc had visited the place often, which was how he had met the cop.

That test passed, Doc took a cab to the unusual ferryboat home of the late Elmer I. Ivers, banker and financier.

The home was under police guard. Two uniformed patrolmen. Doc walked up boldly and showed them a card which bore the misleading statement that he was Joshua Wheels, a syndicated newspaper columnist. Mr. Wheels was important and carried weight with the police department.

"You say you have permission to examine the boat?" said one of the officers. "I will call headquarters and check on that. Just a moment."

He went away and came back.

"Good, Mr. Wheels," he said. "It is all right. Would you like us to go with you?"

Doc had thoughtfully taken the precaution of telephoning Mr. Wheels, whom he knew very well. He had arranged for Mr. Wheels to get himself permission to make the examination of the ferryboat which Doc intended to make in his place.

"One of you might accompany me, to explain to the servants," Doc said.

He proceeded to give the place a thorough half-hour examination, without making much show of doing so.

"There are several servants aboard, now," he remarked. "I understand that, the night of the murder, there were no servants on the boat."

The policeman, visualizing his name in the widely read Joshua Wheels syndicated column, explained, "Yes, true. They say they were summoned hurriedly to the office of their employer’s lawyer. The summoning was done by telephone, and it was the voice of their employer, Mr. Ivers, who talked to them. That is how Mr. Ivers happened to be alone on the boat when Doc Savage came."

"The servants must have been away some time."

"Quite a while," admitted the officer. "You see, the voice on the telephone told them to wait at the lawyer’s office until he—the voice that said it was Mr. Ivers—arrived. So they waited around for hours."

"You talk as if the voice did not belong to Mr. Ivers."

"We have no proof, but we think it did not."

"Who do you think it was?"

"I understand the district attorney is working on the theory that it was Doc Savage. It is known that Mr. Savage is an excellent imitator of voices."

"Have you any ideas on the point?"

The officer hesitated. "To tell the truth, I think they are making a grisly mistake in trying to saddle this thing onto Mr. Savage." He frowned. "That isn’t a popular opinion, right now. But I know criminals have always feared Mr. Savage. To me, that is a good sign."

"But someone," said Doc, "decoyed the servants away so that Mr. Ivers could be murdered?"

"Someone also telephoned the police a tip that Mr. Savage would arrive and murder Mr. Ivers, which was how the police happened to be here. To me, that means Mr. Savage was framed." The officer put out his jaw. "It sickens me, the way people are turning on Mr. Savage and trying to hang this thing on him just because they can’t find anyone else who might be guilty of those invisible-box things."

"Have you any ideas on the invisible boxes?"

"Some kind of a trick, must be," said the officer. "Anyway, they shouldn’t turn on Mr. Savage. He has done a lot of good, I understand. And you take a man criminals are afraid of—that man is all right."

"Human nature," Doc suggested.

"Rat nature, seems to me," said the policeman.

DOC SAVAGE turned up next at Fanning’s Funeral Home, a subdued and expensive establishment. It was here that the body of Elmer I. Ivers lay.

Doc gained admission, and an inspection of the body, by the same device he had used at the Ivers ferryboat home—pretense of being Joshua Wheels, the columnist.

He saw at once that the body of Ivers was in expensive afternoon attire for interment.

"Where are the clothes he was wearing when he died," Doc inquired.

Astonishingly enough, they had them. "They are here," the attendant said, opening a metal cabinet.

Doc arranged the garments on the table. He inspected them, but did not touch them or turn them after he had spread them out.

They consisted of the pants of a tuxedo, a white shirt of the semi-dress variety with a spotless bosom, a smoking jacket, black leather pumps, and such accessories as black tie and onyx cuff links to go with the outfit. Doc Savage examined the spotless shirt front in particular.

The odd point was that he remembered there had been a brown stain, as if a pipe had drooled, on the shirt front of the man who had said he was Elmer Ivers and admitted him to the ferryboat.

Doc went back and looked at Ivers’ body again.

It was not the Ivers who had admitted him to the ferryboat. This was a different man. Not the same man, not the same clothes.

"Quite sure this is Elmer I. Ivers?" Doc asked.

"Oh, quite sure," said the attendant. "The police say so."

Doc Savage took the dead man’s fingerprints with an outfit which he had foresightedly brought along.

"Why do that?" asked the astonished attendant.

"Hobby," Doc told him.

ON his way downtown, he stopped off at a telephone to get in touch with the writer, Joshua Wheels, and explain, "You have visited the Ivers ferryboat and talked with a policeman named Jones who thinks they are making a mistake trying to hang this on Doc Savage. Next, you visited the Fanning Funeral Home and looked at Elmer Ivers’ body twice, and also at the clothing he was wearing when he was killed. You also took Ivers’ fingerprints."

"I’ve been busy, haven’t I?" said Joshua Wheels.

"And next you will go downtown to the bank of which Mr. Ivers was president, and you will get Mr. Ivers’ fingerprints."

"How do I know they’ll have his fingerprints?"

"It is the custom to fingerprint bankers, usually. In case you do not get them, you are going to be disappointed and ask a lot of questions aimed at finding where you can get a set of fingerprints which are surely Mr. Ivers’."

Joshua Wheels chuckled. "Call me up and let me know when I get done doing such strange things," he said. "I wouldn’t want to be two places at once, but I do have an appointment with a radio chain for two hours from now."

"You will hear," Doc told him.

The bank had the fingerprints of Elmer I. Ivers, they said. A vice president sent a clerk looking for them. Then, after time had dragged past, the vice president got up to see what was keeping the clerk.

Later the vice president returned, a bit ruffled.

"Very sorry about this," he said. "Seems our file girl has gotten the files mixed up and, unfortunately, we cannot find Mr. Ivers’ fingerprints."

Doc Savage’s eyes—their flake-gold color was concealed by colored optical caps which fitted directly on the eye pupils—narrowed.

"You mean," he said, "that the fingerprint card has disappeared?"

The vice president took out a handkerchief and wiped the wet beads off his neck.

"Nonsense," he insisted. "We will find it."

Doc Savage made the kind of a remark that Joshua Wheels might have made.

"It will be a very hot day when you do, I imagine," he said.

He left the bank with a conviction.

Elmer I. Ivers had been dead when he came to the ferryboat that afternoon. Already murdered. The fake Ivers had met Doc, planted the scene by summoning the police previously, and everything had clicked to schedule.

There was still the problem of the disappearance of the fake Ivers from the ferryboat.

Doc got the genuine Joshua Wheels on the telephone again.

"You have to pay Ivers’ ferryboat another visit," he told Wheels. "Could you cancel that radio appointment?"

"Is it important?"

"Six people, at least, have died. The lives of that many more are in danger."

"Consider the appointment canceled," Wheels said.

JONES, the policeman who did not believe Doc Savage was guilty, was as cordial as he had been before. But he accompanied Doc on this inspection also, which was not to the bronze man’s liking. There was no way, however, of getting rid of Jones without arousing a possible suspicion.

"What brought you back, Mr. Wheels?" asked the officer.

"Doc Savage insists that there was a fake Ivers who met him and that the real Ivers was already dead in that room. The fake Ivers ran into the room containing the body, shut the door, then screamed and carried on. Then he escaped, leaving the body of the real Ivers where it had been lying dead."

"I hadn’t heard that story," said the astonished Jones.

They went to the murder room.

"Could we get a hammer from the servants?" Doc suggested.

They could. The bronze man went over the walls, tapping, not missing a square foot of space. He got no suspicious sounds. Then he tried the floor. There was a rug, which he rolled back. But no results.

The ceiling was very high; this had originally been one of the upper decks of the ferryboat. It was covered with plywood.

"What is above?" he asked.

Roof, the servants seemed to think. So the bronze man got a stepladder, climbed atop it, tried different parts of the ceiling and found a panel that lifted upward.

Jones, the policeman, gasped in astonishment.

Doc Savage climbed through the aperture. He showed Jones a rope ladder, evidently an ornament from some part of the boat. He dropped it down, and Jones climbed it without trouble to join Doc.

Doc said, "The way the murderer escaped."

Jones was excited. "Then the killer was not Mr. Savage. I’m glad to learn that, Mr. Wheels."

The place where they crouched was space between room ceiling and curved roof. It was about three feet high where they were, less elsewhere.

They began crawling and came out on an upper deck. The spot was exposed to the cold sweep of river winds, but it was also in plain view.

"The killer could not have escaped this way," Jones said.

"Why not?"

"I was one of the police party watching this boat that night," Jones explained. "This deck was watched. Men were posted here. In fact, Lieutenant Blosser personally was up here, I think."

"That makes it look bad for Savage again," Doc suggested.

"It sure does," said Officer Jones regretfully.

Doc said, "Will you inform Commissioner Strance of this development?"

"Sure."

THE bronze man left the ferryboat and telephoned Joshua Wheels again.

"You have turned up a surprising development in the Savage and invisible-box mystery," Doc told Wheels. "Your findings lead you to feel that a fake Ivers met Doc Savage when he came to the ferryboat that afternoon. The real Ivers was, at the time, dead. The fake Ivers led Doc Savage to the scene, dashed into the room with the body, created an uproar to attract the police, then fled by a more-or-less secret exit leading to an upper deck. Thus, the police were presented with what had to be a murder perpetrated by Doc Savage, or a locked-room mystery."

"I think I had better see that this gets publicity," Wheels remarked.

"Thank you."

"Don’t mention it," Wheels said. "I’m happy to step on the toes of District Attorney Einsflagen. The fellow is a trifle ruthless about his ambition."

Doc said, "You have ceased being a dual personality."

"Good. I can just make that radio appointment after all."

DOC SAVAGE went next to the vicinity of the police station to which Lieutenant Blosser was assigned. He entered a telegraph office. He spent some time head-scratching over a pencil and paper and eventually managed to wangle his way into conversation with the manager.

The telegraph office was a small one, with one man serving as manager and operator of the teletype machines over which the messages were sent and received. Doc presented a very credible story about being an ex-operator of "mux," as the teletypes were sometimes called. He called the job by its trade term of "puncher," and began bragging a little.

It was a tribute to the bronze man’s personality that he managed to strike up a bosom acquaintance with the operator-manager in not more than fifteen minutes. He told the fellow how fast he could punch out messages. It was a tall story, and the operator professed disbelief. Doc Savage got around behind the counter to demonstrate.

"I will run off a few words first to limber up," he explained.

He wrote:

LIEUTENANT LARRY BLOSSER POLICE DEPARTMENT NEW YORK CITY—WILL BE AT POLICE STATION TO MEET YOU AT FIVE O’CLOCK TODAY WHEN YOU GET OFF WORK—CALL MARY AND TOM FOR ME—AUNT SUSAN—STONEHAM, CONN., 9:45 A.M.

Then he wrote:

THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG. NOW IS THE TIME FOR ALL GOOD MEN TO COME TO THE AID OF THEIR PARTY.

Following that, he said, "Now, here is what I mean."

He proceeded to strike awe into the puncher-manager by showing what speed could be made on the teletype. It was the simplex variety of machine which printed directly on a tape, instead of being a page printer.

LATER, he sauntered out of the telegraph office.

He had the tape containing the message he had punched to Lieutenant Blosser in his pocket, as well as a blank and an envelope which he had lifted.

He pasted the tape on the blank in the proper fashion, put it in the envelope, then carried it into the police station.

But, growing suddenly prudent, he left without trying to deliver the message, found a taxi with a large driver, and borrowed the man for the job, at an expense of five dollars.

The taxi driver swallowed the story that it was a gag on one of the policemen—which it was, in a way of speaking.

Chapter X. TRAIL TURNS

LIEUTENANT BLOSSER took the telegram when he came in to write out a report. He was only idly curious. Then he read it, and his gloves fell from under his arm, where he had been holding them.

His left arm began trembling, the left side of his face twitched. It was a nervous difficulty which manifested itself in moments of extreme stress.

Blosser left the police station as if pursued by an animal, ran around the corner to a parking lot and piled into his car. He drove recklessly.

On Eighty-first Street, west of the Park, he piled out, opened the door of a garage, then drove inside. It was gloomy in the garage, which was a huge place not in use, as far as storing cars for the public.

Inside the garage stood three trucks, one of them the huge machine in which Ham’s car had been loaded so unceremoniously a bit earlier. There were four passenger automobiles. None of these were new.

There was a young man leaning against a balcony across the back, a rifle to his shoulder.

Blosser yelled, "Be careful with that thing, Nick!"

The man on the balcony lowered his rifle.

Blosser dashed forward, bounded upstairs to the balcony. "Where is my dad?" he barked.

Nick jerked an indicating thumb; he started to say something. Blosser dashed past him, acting so excited that Nick followed. They passed through a door, close together.

Then Nick remembered something.

"Hey, you didn’t close the outside door!" he complained.

"Go close it," Blosser snapped.

Nick swore, returned and descended the stairs, closed the door to the street. He waited there for a while, watching a mirror which had been attached outside a window in the door. The mirror, small and hardly noticeable, afforded a view of the street in one direction; and there was a second mirror for inspection of the other end of the street.

Satisfied that no one was in sight, Nick went back to the balcony. He entered a room in which a man was tied to a chair.

The man tied in the chair looked very much like Blosser. The difference between them was one that could be detected readily enough when they were side by side. But separate them, and it would not be easy to distinguish.

It was a father-and-son resemblance, helped out a little by hair bleach.

Blosser had confronted the older man. Blosser looked ashamed of himself. But he still had his determination.

"Look, dad, I’m in a spot," he said.

The older man said nothing. His face was very sad.

"Look, I got a telegram from Stoneham," said Blosser. "It was from Aunt Susan. She’s coming at five o’clock when I get off work."

The older man was still silent.

"She’ll recognize me," Blosser said wildly. "She won’t be fooled. The cops were taken in, but Aunt Susan won’t be."

"What do you want me to do?" asked the older man.

Their voices, like their appearances, were startlingly alike. The same small mannerisms, the same slight touch of south Brooklyn.

"You have to meet Aunt Susan, steer her away from me," said Blosser.

The other shook his head sadly.

"No," he said.

Blosser clenched his fists. "Look here—this is vital. You have to, see. This has gone too far to have it upset, now. I have the cops fooled."

"No!"

"I have the cops fooled," Blosser repeated. "They think I’m you. They have to go on thinking that. I exchanged places with you, and made the police believe I was you, and got away with it. I’m on the inside. I have to stay on the inside. I have to do that because I have to pick up information that he needs."

"Who is he?"

"The guy with the brains." Blosser sneered. "If you think you get told more than that, you’re crazy."

"No."

"You won’t do it?"

"You know that without asking."

Blosser breathed inward slowly and deeply. "You know me, dad. Nothing stands in my way. I’ll kill you if you don’t do this for me."

The older man shook his head. There was a kind of complete simplicity in the gesture.

"No!" he said.

Blosser took a gun out of a pocket. Not his service revolver, but a smaller weapon, a single-shot pistol of small caliber and short barrel. A gun which would kill a man as completely as a .45, if aimed carefully, but not make much noise.

Doc Savage came out of the adjacent shadows at that point!

A STOOL, a three-legged wooden stool, actually preceded him out of the shadows. He threw it with care, accuracy. It turned over twice in the air, struck Blosser’s gun hand. Blosser lost the gun.

Doc came not quite, but almost, as fast as the thrown stool. He struck the man with the rifle, Nick, with the edge of his hand at the throat. He grabbed the rifle out of Nick’s hands. Nick staggered, sounding like a toy balloon with the air leaving it. Doc hit him. Nick became silent.

Blosser was fumbling for his service revolver with his left hand. His right-hand thumb was sprained, and one finger was back in a shape it should not have been, out of joint.

Doc came toward him. Blosser stopped fumbling for his gun, tried to square off. Doc stamped on one of his toes. Blosser’s guard came down. Doc’s knuckles slid just enough after they landed on his jaw to remove some skin. Blosser hit the floor like three or four sticks of loose wood.

The old man sat in the chair, staring at Doc, but not straining against the ropes which held him. He did not say anything.

Doc Savage picked up the rifle and looked through two other rooms opening off the balcony. He went down the stairs and looked in what had once been a room for the garage mechanical department. There was no one.

He examined the trucks, the cars. No one was in them. He looked over the interior of the cars and truck carefully. In one, he found a short rusty-looking hair bristle. It could have come out of a clothes brush; but more likely it was one of the hairs off Monk’s pet pig, Habeas Corpus, which had dropped off Monk’s clothing.

In the van body, he did an unusual thing. He produced a small gadget, similar to a flashlight, but with an opaque lens. It was a projector of ultraviolet light, and he began going over the truck interior with it.

He found nothing in that truck.

In the other truck, he found his armored limousine. This was apparently the machine in which Ham, Pat, Jen Bridges and Uncle Joe Morgan had been riding with Lieutenant Blosser when another car bumped them from behind and knocked them up into a truck ahead. This, of course, was obviously the truck.

In the sedan, written on the back window, was a message in green fire. Not literally fire, of course. The stuff was a trace of chemical writing left by Ham; he had used a special button off his shirt for the enscribing. Normally, it was unnoticeable. But, under ultraviolet light, it fluoresced brilliantly. So brightly, in fact, that it could almost be read in daylight.

Ham’s message:

They trapped us with the old truck gag. I must be slipping! They are going to run their truck and our car into the river if we don’t come out. They will lock the truck on the outside before they do that; so we will have to give in, I guess. For some reason, they do not want to kill us. I think there is somebody important to their plans who won’t continue helping them if we are killed.

Monk, Renny, Johnny, Long Tom have been caught. Pat, Jen, Uncle Joe with me. So they have us all.

I still do not have the slightest idea of how to explain the invisible-box murders, or what is behind it.

Ted Parks, the young doctor, is important. And they are mentioning someone named Rensance.

Ham.

Doc finished the remarkably complete message. Ham must have had plenty of time to write it.

DOC SAVAGE went back to the balcony. The older man tied to the chair stared at him. The fellow still had not said anything.

Doc said, "You are actually Lieutenant Blosser?"

The other nodded.

"If I turned you loose," Doc said, "what would you do? Hope that you would be able to snatch up one of those guns and save the situation?"

The older Blosser gaped in utter astonishment.

Doc Savage went over and examined Nick, who showed signs of returning to his senses. Doc hit Nick again, not hard enough to permanently wreck him, but a clip that would extend unconsciousness.

Young Blosser was stirring, mumbling. Doc shook him, slapped his face lightly. Blosser finally got his eyes to focus, and they fixed on his disjointed finger.

Doc gripped the finger, pulled, set it back in joint. Sudden sweat appeared on Blosser’s forehead, but he did not make a sound.

Doc faced the older man in the chair.

He said, "A son kidnapping his father and taking his father’s place on the police force—it could not happen." He glanced from one Blosser to another. "It is too fantastic. And you two men are not in character with such a thing. Your son would not do such a thing to his father. There are—I am glad to say they are rare—sons who would do such a thing. But not yours."

The older Blosser twisted his lips.

"I hope they are not as perceiving as you are," he said.

"They?"

"Whoever is behind this."

"You do not know that, of course." Doc said this as a statement, not a question.

The older Blosser eyed him in surprise. "You seem to have come to the truth."

Doc said, "Is it a police trick?"

"You think it is?"

"Yes."

Blosser sighed. "That’s right." Then the older man shuddered. "But if those fellows get wise—" He moved his eyes and mouth to imitate a dying man. "What tipped you off?"

"It became obvious that the murderer of Elmer Ivers escaped from the ferryboat past the spot your son was guarding. Only two conclusions could be drawn from that: either you were a crook, or your son had taken your place with your knowledge. There have been cases of a son kidnapping his father, but the people in such cases were not the caliber of you and your son."

"Thank you," the elder Blosser said.

The younger Blosser glanced anxiously at the unconscious Nick. "If this guy wakes up and hears this, the beans will be spilled."

"He will be unconscious some time yet," Doc said. The bronze man swung to the elder Blosser. "Let me have the story."

Blosser hesitated.

His son said, "Go ahead, pop. I think the department has been making a mistake all along about Savage. I don’t think he’s guilty."

The older Blosser swallowed.

"We are both policemen, my son and I," he told Doc Savage proudly. "Larry, here, is an undercover man. He speaks several languages, and he understands foreign customs. As a matter of fact, he is a member of the section of the police department assigned to ferreting out foreign espionage agents—a section of police activity about which the public knows nothing, incidentally."

The elder Blosser glanced anxiously at Nick.

"Larry first heard of this thing when the rumor came around to him that a mysterious individual was assembling a sinister organization of some sort," Blosser continued. "Dangerous criminals, clever ones, were being employed and paid large sums."

"A foreign agent at work?" Doc suggested, but not as if he believed this was the motive.

Blosser stared at him. "I can tell by your tone that you know it wasn’t. No, it is not a spy or sabotage thing. Of course, we thought at first that it was. That is how Larry came to get interested in it. Larry was assigned to sabotage-investigation activities, as I told you."

"What is it, then?"

"Frankly, we don’t know."

"Do you know how the invisible-box murders are committed?"

"No."

"Or why they were committed?"

"No."

The bronze man’s flake-gold eyes narrowed. "Just what have you learned?"

"That the individual behind this has gone to great pains to keep his identity secret, and is succeeding," Blosser said. "Names have been mentioned. A doctor named Ted Parks is involved somehow."

"In what way?"

"Larry here has just heard talk that leads him to believe Parks is the brains behind it."

"Have the police looked for Parks?"

Blosser nodded. "They can’t find him."

"Why were the murders committed?"

"We don’t know."

DOC SAVAGE paused, went over to Nick, and made sure the man was still senseless. Coming back, he said, "Are you telling me that the police department knows what you are doing and is working with you?"

"Of course. Do you think Larry could have taken my place otherwise? The police department is not that gullible."

Doc pounced on this point. "Just what was the idea of Larry, your son, taking your place?"

"After Larry heard these rumors about a sinister organization being formed, he wangled around until he got himself into it as a member. They investigated him thoroughly, particularly the point about his father being on the police force. Larry has never made a secret of that in his undercover work, or of the fact that he used to be a policeman. You see, that’s what he always says: that he was a cop and got bounced. That’s his story."

"Larry pretends to be a crooked cop who got fired?"

"Right."

"And so?"

"Out of a clear sky came the order to kidnap me and take my place," said Blosser. "We talked it over and decided to do it. We didn’t know what the idea was."

"They gave a reason for your son’s taking your place?"

"Oh, of course!"

"What was it?"

"So my son could get inside information for them on the progress the police were making toward solving the invisible-box murders."

Doc Savage was silent a moment; then his trilling seemed to come into existence, a sound so low that it hardly left his throat. He said, "Which does not explain how your son let the murderer escape on the ferryboat."

"Larry didn’t know there was to be a killing," said the older Blosser grimly. "He was told to get on the police detail assigned to the ferryboat, if he could. And he did. He was told that a man would leave the boat by the upper deck, sliding down a rope into a rowboat concealed under the dock. This man would move the rowboat along by hand to the mouth of a large drain pipe, which emptied into the river at that point, and hide in the mouth of the pipe until the excitement was over. This was what Larry did and let the man escape. Then he found out there had been a murder, and he went to get the killer. But the fellow hadn’t waited in the pipe. He had escaped."

Doc swung to young Blosser. "That right?"

The younger man nodded. "Every word the truth. It sounds wild, but there it is."

"And you do not know the motive for these murders?"

"No."

Doc Savage picked up the rifle which Nick had carried and the two revolvers young Blosser had brought—the service gun and the small single-shot pistol. He tucked the rifle under an arm and dangled the revolvers from a finger.

He went to young Blosser.

"Nick will get back to his senses soon," Doc said. "When he does, tell him he has not been unconscious long. Tell him you drove me off. Tell him I fled. Tell him you have to get out of here in a hurry."

The youthful Blosser eyed him. "Meaning you want to get Nick on the run, so he will maybe lead you to the higher-ups?"

"Right."

"Good!" Blosser got to his feet. He extended a hand. "Give me my service gun."

Doc extended the revolver.

Blosser took the weapon, reversed it, pointed it at Doc Savage’s head.

"Get your hands up!" Blosser said.

The bronze man’s mouth tightened, but otherwise his expression did not change. "So you have been lying to me?"

Young Blosser was shaking in his excitement. "We haven’t told you one damned lie," he said. "There is just one thing we left out."

"You omitted—"

"That we have absolute proof you are the brains behind this infernal thing!" Blosser snarled.

"Proof?" For once, the bronze man’s control was shaken.

Blosser pointed at the man called Nick.

"Nick has told me you are behind it!" he said.

DOC SAVAGE reached out, then, and snaked young Blosser’s gun. There was dazzling speed in his gesture—and careful calculation, because his thumb dropped on the hammer, holding it back. The gesture was not as reckless as it looked. The gun was pointed at his chest at the moment, and he wore a bulletproof undergarment.

They fought then, briefly, violently! Blosser ended up on the floor, expelling a tooth and profanity. Doc found a rope, a tow rope from one of the trucks, and tied him.

Soon after that, the man called Nick opened his eyes, did some groaning, and got himself organized. He stared at Doc Savage.

Both Blossers seemed to hold their breath as they waited for Nick to speak.

Nick said, "Boss, why did you have to hit me?" He looked straight at Doc Savage, and his voice was sincere as he said it.

Young Blosser expelled his breath, grimly satisfied. The older man dropped his shoulders wearily.

Doc Savage’s face suddenly—like an actor going into a part—began to show expression. He frowned. His brows beetled. "Who told you I was head of this thing?" he demanded.

"Why, I got that from—" Nick stopped.

"From whom?"

Nick squirmed. "Listen, I haven’t told anybody."

"You told them!" Doc indicated the Blossers.

Nick wheeled and cursed young Blosser. "We oughta knowed better than trust an ex-cop!" he snarled.

"Who gave you your information about me, Nick?" Doc Savage persisted.

"I . . . er—" Nick swallowed. "I can’t tell you, boss."

"But the man told you I was the leader?"

"Sure! The whole organization knows that. They know you were trying to keep it quiet, but there was a leak somewhere. That was why you had your friends—that Monk Mayfair, and the others—grabbed."

Doc’s tone was ominous. "Why did I have them seized?"

"Oh, the organization understands that! They don’t know you are the brains in this thing—your friends don’t, that is. But they began to get suspicious. So you had to get them out of the way. You ordered them grabbed. They aren’t to be killed. They are just to be held until this thing is settled."

"So that is why Monk and the others are not being killed?" Doc said.

"That’s the talk."

"And what about Uncle Joe Morgan?"

"Oh, him!" Nick shrugged. "You just had him marked for one of your victims."

"Victims in what?"

Nick looked uncomfortable. "Whatever you’re pulling. you know as well as I do that none of us has been told what is behind this."

"And what," asked Doc Savage, "about Ted Parks?"

"He’s in with you. He’s your partner."

"Parks is my partner, eh?" Doc Savage began to lose expression, to resume his normal composed manner. His voice also lost its emotion. "What do you know of Jen Bridges and her brother, David?" he inquired.

"Them?" Nick shook his head. "Nobody in the organization can figure out who they are, or where they hook into this."

Doc Savage straightened. "But you are positive I am your leader?"

Nick stared at him. "Who you kidding?"

"You think I am deceiving you?"

"If you claim you ain’t the boss," Nick said, "you are kidding me. I know you are. I know because I have heard you talk to the organization and issue orders. I recognize your voice. And we found your fingerprints on a telephone you had used. One of the boys used to be a fingerprint man; and, just for fun, he took the prints off the telephone and checked them with your prints, taken off a glass in a restaurant where we watched you eat. They were the same. You’re the boss, all right."

Doc struck Nick on the jaw and put him motionless on the floor.

Chapter XI. MAN DANGER

NICK escaped ten minutes later. It might have been somewhat less than ten minutes; it was as quickly as Doc Savage could arrange it.

The bronze man first walked over and tested the bindings of the two Blossers. Then, carrying his captured guns, he strolled down the stairs to the cars.

Under the back seat of the least conspicuous car—which was also the slowest—he placed a small fiber case. The case, although not large, was the most bulky thing that had been in his pockets. A little larger than a kitchen match box. He had some trouble getting this up under the cushion springs in such a spot that it would not be noticeable, should anyone sit on the cushion.

He started the car motor and left it running, as if to warm up.

He went up to the balcony, picked up Nick, carried him down and put him in the car.

He had not tied Nick. He made a business of looking around for rope. "Any rope up there?" he called to the Blossers, who naturally did not answer him. Then he went back to the balcony, as if seeking rope.

Reaching the balcony, he dropped to a knee beside the younger Blosser.

"Nick wasn’t hit hard enough to make him unconscious," the bronze man said. "He will try to escape. I am going to follow him. You two try to get it through your head that someone is taking infinite pains to get me into trouble. Try to understand that. Notice that Nick did not know I was his leader. He had just heard I was. Nick’s misinformation was part of—"

The car suddenly meshed gears on the garage floor below. Doc jumped to the railing. To make it good, he yelled. He also fired a pistol, directing the bullet into the floor.

Nick was a scared man. He sent the car headlong at the garage doors, managing to get enough speed so that, when he hit the doors, they burst open with splinters and dust and noise. The car, sadly battered, dived out into the street.

Doc Savage was not pleased. He had not figured the man would be fool enough to drive headlong at the door, batter up the machine so that it might have to be abandoned immediately.

Abandoning the car would, of course, render useless Doc’s small radio transmitter which he had planted under the seat with the idea of using a direction finder to keep track of the car.

The bronze man lost no time leaving the garage. He ran until he located a taxi, though Nick and the battered car were gone, by now. Doc told the driver, "Amsterdam Avenue, and fast." Then, on Amsterdam, he said, "Turn right, six blocks." And at the end of the half-dozen blocks, "Stop here!"

The building was as shabby as any on Amsterdam. Doc dropped down a basement stairway, manipulated a lock, at the same time holding a palm against a brick at the side of the door in what could have been an innocent gesture, but wasn’t. The hand on the brick operated a capacity-type device which unbolted the door. He went in.

This was the laboratory of Long Tom, the electrical wizard of Doc’s organization. Because Long Tom liked seclusion when he worked, few outside the group knew of the place. Doc felt sure the police would not have a guard over it, and he was positive there would be a portable radio direction finder in the place. There was.

Also a great help was the car which Long Tom kept in an adjacent garage. The car was an elderly rattletrap containing a tank-type motor, which meant an airplane motor, liquid-cooled.

THE man called Nick left his battered car in the north Bronx, near the Westchester line. He simply parked the car, walked two blocks to a street-car line, got on a car and rode. Later, he transferred from the street car to a bus.

Doc Savage followed him in Long Tom’s old automobile. Later he left the car and moved on foot after Nick, as Nick entered a lunchroom.

It was a dining-car-type lunchroom; the clients sat with their backs to the windows, facing the counter and the back bar, which was all shining chromium where it was not steaming coffee urns and polished toasters. Nick ordered coffee.

Soon, a man came and sat on the stool beside Nick. The two seemed to exchange no words. But they left together.

From this, Doc surmised the hideout was near and that the lunchroom was being used as a precautionary contact point, to make sure the coast was clear.

They went, Nick and the man who had met him, to a residential street, where they entered a brick house. It was almost dark by now, and a flash of light showed from the house interior as they opened the door and went in.

Doc Savage moved around to the back. He was carrying Long Tom’s radio direction finder, because the device was a gadget of more than one use. The amplifier part of it, for instance, could take a tiny quantity of sound, a fractional decibel of it, and step this up to a blast.

The bronze man attached a sensitive contact microphone to the panel of the rear door, hitched it to the amplifier, then fed the tubes volume.

What he got was disappointing. A refrigerator ran noisily somewhere in the house, its vibration interfering with such noises as were words. One thing he did learn: there was no guard inside the door. So he tried the door. Locked.

He used his belt buckle on the glass in the door. The belt buckle looked cheap. He used the end of the tongue, or, rather, the tiny diamond that was set in the tip of the tongue. The diamond could groove the hardest alloy steel, so the glass did not give it any trouble. He waited until a car went past, tapped; the glass came out, and he reached in and unfastened the lock.

The place where he stood, now, smelled of food, so it was evidently the kitchen. He went on. He heard feet coming down stairs. Then voices. He got close to the voices and listened.

One voice said, "Hello, Nick. What has happened?"

"I’ve got up against something I don’t understand," Nick said. "Doc Savage has broken out of jail. He talked to me, and he acted as if he ain’t the boss. In fact, when I told him he was, he bopped me on the jaw. He started to load me in a car, I don’t know what he planned. I got away."

"How come you made the break?"

"I got the idea he was mad because I let the cat out of the bag about everybody knowing he was boss. So I tried to cover up by skipping."

"You think he was actually mad?"

"If he wasn’t, he was acting darn funny."

Doc Savage’s metallic face was grim. They actually thought he was their employer. The situation had not seemed believable, but now he was convinced.

It was, on the whole, clever, and diabolically so. It indicated an agile brain as well as a tenacious and fiendish one. What better basis for starting a criminal enterprise than to build up an identity as another man, particularly one notable enough that there could be no doubt about what individual you were pretending to be?

Nick’s words stabbed into Doc’s summary.

"What about the Rensance thing. Joe?"

"That goes through tonight," Joe said. "This Rensance is being blockheaded about it, so that’s too bad for him."

"Are all the prisoners here?" Nick inquired.

"No. Orders came through to only keep the ones we got with the Ted Parks trick up at that old amusement park."

"That Monk, Long Tom, Johnny and Renny?"

"Right. They’re here."

Doc Savage tucked his apparatus under his arm and walked into the room where the two men were talking.

"Take it easy, fellows," Doc said in a calm tone.

They gaped at him.

To Nick, Doc said, "Sorry about the tap on the jaw I gave you. It was a little distressing to find out that my identity was not the secret it was supposed to be."

Nick exhaled relief explosively. "So you are the chief!"

Doc made no comment on that. Because he was a man who always went to great pains to do exactly whatever he said he would do, and to be whatever he said he was, he did not commit the trivial deceit of telling Nick he was his leader. He was, however, letting Nick draw that conclusion.

The distinction between deceiving a man, and not actually lying to him, was one which Doc Savage was careful about. Monk and the others were moved gleefully to declare that Doc Savage had never actually told a lie.

Nick was deceived. The other man, likewise.

Doc asked, "How many of the boys are here, Joe?"

"Why, just Jig, upstairs watching the prisoners," said Nick’s companion. He was a round blond man with flashing white teeth and only a certain scraped-bone grayness in his eyes to indicate his vicious character.

"Sit down," Doc said, "and tell me how things are going."

Joe licked his lips. He was extremely interested in Doc Savage.

"You mean about Rensance?" he inquired.

"Right," Doc said calmly.

Joe was evidently an ambitious boot-licker. He expanded, began to fawn. He fell over himself to offer a full explanation.

"It’s all set," he said. "Rensance has balked. So the word is to knock him off. But you would know what the word is." Joe grinned at Doc Savage. "It’s all set."

"Do you know the exact details?"

"I . . . er . . . sure." Joe was somewhat uneasy, for he might have felt that he shouldn’t know the details.

"Repeat them," Doc ordered. "Let us see if anything has been balled up."

"The gang is to close in on Rensance at nine thirty," Joe said. "They are to meet at the abandoned gatehouse on the estate. At thirty-five past nine, the man will show up with the—whatever it is."

Doc took no chance. "The whatever-it-is?" he repeated and waited.

"The invisible-box business."

"You do not know what the murder method is?"

"Not me." Joe sighed. "That’s one thing I don’t know."

"How long," asked Doc, "would it take to get to Rensance’s place?"

"Not long," Joe said. "Half an hour, maybe."

Doc Savage made elaborate show out of looking at his watch. "Care to go there with me, Joe?" he asked. "I need a driver to the spot."

Joe sprang to his feet. He was eager to get in solid with the big boss.

"Sure, sure!" he said. "You should see me drive. I used to tool a car for Legs Diamond in the old days."

They left the building, walked down the street, reached the car in which Doc Savage had arrived. They climbed in the machine.

Doc went through the motions of a man who had forgotten something—exclaiming, snapping fingers.

He said, "Wait here. I want to tell Nick something." To make Joe less suspicious, he added, "To tell the truth, I do not trust Nick too far."

JIG, the man watching the prisoners upstairs, had no eyebrows. There was nothing else peculiar about him. He was a long, lean man of nondescript feature and average clothing. But he had no eyebrows.

Nick said, "This is the chief."

Jig said, "Pleased to meet you, Mr. Savage." He extended a hand.

Doc took the hand and put on pressure. The pain doubled Jig forward for a moment. Doc slapped him on the back while he was doubled over. It was a robust, friendly slap.

"Great fellows, all of you," Doc announced.

He gave Nick a hand-shaking and a slap on the shoulder for good measure, which somewhat astonished Nick.

Both Nick and Jig looked at their aching knuckles and, still looking at them, sank down to the floor. The sinking was not immediate, but it was complete.

Doc removed the hypodermic ring which had been on his finger when he did the back-slapping; it would repeat and inject half a dozen doses, if necessary, of unconsciousness-producing drug. He placed the ring in the metal case where he ordinarily carried it.

Monk, Renny, Long Tom and Johnny were sitting in large overstuffed chairs, hands tied, faces taped. Doc removed the tape. They began coughing up sponges.

"I’ll be superamalgamated," said Johnny, spitting sponge. "Pyrotically invidious phylum porifera."

Long Tom stared at him. "Says which?"

"I was eating that damned sponge so I could yell for help," said Johnny in small words. "I had it half eaten." He looked displeased.

Doc untied Monk and indicated he was to free the others.

"Listen," Doc said.

They gave him attention.

"It stands this way," Doc said. "Mysterious murders. Invisible boxes. No reason. Uncle Joe knows the victims. So does Ted Parks. Parks has vanished mysteriously. We begin investigating. So they start framing the killings on me. Jen Bridges comes to us with a story of a brother who has been kidnapped, but the story has not been substantiated. I was put in jail. You were grabbed in a body and held here. Ham, Jen Bridges, Pat and Uncle Joe Morgan have been grabbed, also, and are being held elsewhere."

The bronze man broke his summary off for a moment. Then he said, "That is all repetition. But I want you to get it straight."

Monk said, "About the radium miner, the man who slept three weeks, and the people who’ve bought monkeys—where do they come in?"

Doc seemed not to hear that.

He said, "The latest victim intended seems to be named Rensance. I have tricked the thug named Joe into taking me there. You fellows follow. Be ready for action."

Long Tom said, "We have no weapons."

Renny blocked out his big fists, rumbled, "These are all the weapons I need." He was angry.

"Me, too," Monk said hopefully.

JOE was a talker. He did not bother opening the conversation with the weather; he got right to the subject in which he was most interested. Himself. He was a great guy, Joe was—to hear him tell it.

He was not a bad driver. He admired the car, particularly the power of the great motor which Long Tom had put inside the hood.

"You want the police to bother us for speeding?" Doc asked once.

That slowed Joe. Because there was plenty of time, they stopped at a roadhouse and had coffee. The route was taking them north into the section of large estates.

At twenty-five past nine, Joe pulled the car into the brush beside a lane. He got out. Doc followed him. They came to a great stone wall and an iron gate, with a keeper’s lodge of stone close by. The gate stood ajar. They passed through.

It was then nine thirty.

The gate-keeper’s lodge was in darkness. But a door opened, disclosing that there was dimmed light inside.

A voice from the door said, "Get in here before somebody sees you."

They entered the lodge. The man who had called to them threw the door shut, then tripped a switch which made the lights bright. He showed them the business end of a pump-action repeating shotgun, ten-gauge, at least, from the size of its barrel.

"Kindly join my collection," he said.

He was, Doc Savage realized, Ted Parks.

Arranged along one wall were four men. Their hands and feet were tied.

Chapter XII. THE VAGUE MR. RENSANCE

DOC SAVAGE and Ted Parks looked at each other. There was no doubt in Doc’s mind that this young man—large, brawny, shoulders stooped slightly, eyes strained behind thick spectacles—was Ted Parks. In their preliminary investigation of Uncle Joe Morgan and Ted Parks, Doc and his aids had dug up an old picture of Parks.

Parks’ lips parted. He lost color.

"I’ll be damned!" he said hoarsely.

He started to lower his gun, then lifted it again.

Doc Savage paid no attention to his indecision. He turned, tapped the astounded Joe on the jaw with a fist and stretched him out on the floor beside the other prisoners. There was a hank of rope handy. He tied Joe.

"Any more coming?" he asked Parks.

"I—" Parks swallowed. "I don’t know."

Doc said, "There seems to be one special man who does the so-called invisible-box murdering. Has he shown up, yet?"

Parks shook his head. He was bewildered. "I . . . I don’t get this. How did you show up here?"

"A long story," Doc told him. "Let me have your story."

"You are supposed to be in jail," Parks said. "I . . . I’ve been trying to figure how to get in touch with you, since I saw those advertisements for a radium miner and a man who had slept three weeks."

"Those advertisements meant something to you?" Doc asked.

"I’ll say they did!" Parks exclaimed.

Interruption, a voice, came from outside the stone keeper’s lodge. It was Monk. He called, "Doc, everything all right?"

The bronze man held out a hand. "Your gun, Parks." After hesitating, Parks handed over his shotgun.

Doc went to the door.

He told Monk, "The murderer is not here. He was to be five minutes late, I think. Scatter. Watch for him."

"We’ll grab him," Monk declared grimly.

"Do that without warning him," Doc said. "Give him absolutely no warning. And do not go hear him." The bronze man passed several gas grenades out to Monk. "Use these. And whatever you do, don’t go near him."

"That won’t be much fun," Monk said.

Monk liked a physical fight.

"Get close to that fellow," Doc said, "and there is probably nothing that will save your life."

Impressed, Monk moved back in the darkness. With Renny, Long Tom and Johnny, they scattered to keep a watch, dividing up the supply of gas grenades among themselves.

Doc closed the lodge door and swung to face Ted Parks.

"We have time to hear your end of this," he said.

Parks nodded. He looked miserable. His eyes fixed on the floor. "My end of it isn’t very sweet."

"Tell it."

"I guess it wouldn’t have happened to me if I had been a different kind of a guy," Parks muttered. "But I’ve always been as poor as that church mouse you hear about. I’ve had to make my own way. I’ve had one goal all my life—to be a great doctor. Not a surgeon. A specialist in research. Finding cures for cancer, sleeping sickness, treatments for chagres fever, dengue disease, tularemia, and things like that. I’ve worked hard—"

Doc said, "We checked on your past life. It is very commendable."

Parks straightened. "All right, you know my career means everything to me. That is why, when this thing the police call the invisible-box death began striking, I was afraid to go to the police. I was a coward. All I could see was that the thing would result in the Medical Association expelling me, barring me from the profession I’ve spent my life learning."

The grinding agony in his voice showed how he feared being thrown out of the profession.

Doc asked, "The murders were framed on you?"

"The first ones, yes." Parks nodded. "The police do not know it, yet, but they were."

"How?"

"Those so-called invisible boxes were made in my laboratory! I discovered the process."

Doc Savage said quietly, "You discovered the whole murder method, did you not?"

Parks stared at him. "How did you know?"

"A guess. It would take a highly scientific mind, such as you have developed, to do the job."

Parks groaned. "I didn’t discover it with the idea of using it to murder anybody."

Here, one of the bound men made a noise, got their attention. The fellow said with terror in his voice, "What will they do with us for our part in it?"

Parks’ answer was a snarl. "Electrocute you, no doubt!"

The scared prisoner licked his lips. "I ain’t directly guilty. I didn’t know—"

"The hell you didn’t, you yellow rat!" said one of his companions.

The frightened man burst out with what he wanted to tell them, wailing, "The plans were changed tonight! The guy with the—the murderer was to go direct to get Rensance. He wasn’t to come here, until he finished the job. We were to watch the gate. That was all."

Doc Savage took a step forward. "You mean—"

"Rensance may be gettin’ killed right now!" the man wailed. "And remember, I’m tellin’ this to prove I’m innocent of any intent—"

Doc yanked the door open.

"Monk, Ham, the rest of you—watch this place!" he called. "Watch these prisoners!"

He ran toward the distant mansion.

THE house was not actually visible, except as a lump of shadow, a presence in the night rather than a reality. No windows were lighted.

The path had a covering of blacktop composition. Doc’s feet made some noise on it, as little as he could manage. Nearing the house, he paused briefly, stripped off his shoes, carried them.

He pounded hard on the first door he reached. Then he went on. Shrubbery around the house was high, tangled. He waded in it, found there were no doors until he reached the back. Here there was a wide veranda, a door opening from that.

He waited. He heard the door at the front of the house open. No one came to the rear door. No one left by any of the windows. He knocked on the rear door.

The man who opened the door was no servant. Yet, a house this size would have three or four servants, at least.

"Yes?" said the man.

He was an old gentleman, with white hair, clear eyes, ruddy skin. Blue-gray smoke curled from a cigarette in a long holder.

"Mr. Rensance?" Doc asked.

"I—yes."

"Where are the servants?"

Rensance lifted the long holder to his lips, drew in cigarette smoke. "I beg your pardon?" Blue smoke dribbled off his lips.

Doc Savage studied the man. He noticed the fellow’s left hand was a tight fist.

"Has he come yet?" Doc asked.

"Who?"

"The man who was going to kill you."

Rensance did not show by word or expression that the statement meant anything to him. His eyes did not widen; his mouth did not move in the slightest. He lifted the cigarette holder to his lips slowly and drew in long and deep. And the holder snapped in two pieces in his fingers; the cigarette flew upward, a skyrocket of sparks in the night.

Doc put a hand against Rensance’s chest, pushed him back into the house and came in after him. He shoved Rensance down in a chair. He yanked down an elaborate cord attached to a servant bell and tied the man with it. The cord was deep-blue velvet and made a very tight knot.

There was no one in the house when Doc searched it. The only light was burning in a photographic darkroom on the second floor. Evidently, Rensance was an amateur photographer. The darkroom had finer equipment and more of it than many a commercial shop.

Some of the paper on the darkroom floor was crumpled black lightproof sheets from packages of printing paper, some was ruined prints, and some of it was paper bindings off packages of currency.

$1,000.00

$5,000.00

$10,000.00

That was the way the printed figures on the bindings ran. None was smaller than a thousand, none more than ten thousand dollars. Doc gathered them up. There was a good handful. He might have missed some.

He took them down and showed them to Rensance.

"I presume you paid off after all," he said. "How long has he been gone?"

Rensance closed his hands slowly and with force, as if he was molding hard snowballs.

"Half an hour," he said.

"Is there a telephone to the gate lodge?"

"Yes."

Doc Savage located the telephone. At the other end, Monk finally answered.

"Look sharply, Monk," Doc said. "There was a hitch. Our man came here early. There was no murder. Rensance paid off. But the killer may show up there at the lodge."

"So money is behind this, the root of evil," Monk said amiably. "O. K. We’ll peel our eyes for the guy."

DOC SAVAGE swung back to Rensance.

"How did the man happen to come early?" he asked.

"I got in touch with them."

"How?"

"Carrier pigeon."

"Carrier pigeons," Doc Savage said, "roost at night."

"It was before dark. About four o’clock, in fact."

"Have you any more pigeons?"

"One. They just sent me the two." Rensance shuddered. "I know who you are, so I imagine you have escaped from jail and are trying to clear yourself. I did not imagine you were guilty. Yes, they sent me only the two pigeons. I was to use one if I decided to pay. I have one pigeon left."

"How much did you pay?"

"Two hundred thousand dollars," Rensance said.

Involuntarily, Doc made the trilling sound which was his peculiar expression of intense excitement. The sum was enormous. Fantastic!

"Plain extortion?" he asked.

"Nothing else."

"If you had not paid—"

Rensance was getting more ruddy. His skin seemed to have the peculiarity of getting red instead of white when he was intensely disturbed.

He said, "Death, they told me. I was approached a few days ago, after the first three of those mysterious murders the police and newspapers refer to as the invisible-box murders. I was told those men had been killed because they would not pay sums demanded of them. I was informed my contribution was two hundred thousand dollars."

Doc Savage said, "You should have gone to the police and the newspapers immediately with that."

Rensance breathed in and out deeply, the air whistling slightly in his nostrils.

"Newspapers," he said, "are what they kindly sent me, with the suggestion that I read them. I did so. I saw plainly that the police were hopelessly at sea to explain the deaths."

"So you decided to pay."

"No, I went to the police. I told them the whole story."

Doc Savage was taken by surprise. He had not known that. The police, who usually worked with him—they were hardly doing that on this case, however, which was understandable—had in the past kept him informed on such points. He had presumed that the police were in the dark as to the motives.

The authorities were not, it seemed, in the dark. They simply had not turned the information over to the newspapers.

"Your first reaction was not to pay, then," he said.

"Right."

"What changed your mind?"

"You remember the death of Elmer I. Ivers?"

Doc looked at Rensance to see if the remark was some kind of grisly gag. Apparently it wasn’t.

"Slightly," Doc admitted.

The death of Elmer Ivers was only the incident which had led to his being arrested by the police and charged with murder, so he had some cause to recollect it.

"The police knew Ivers was in danger, and they were guarding his boat," Rensance said grimly. "But he died anyway. When that happened, my courage broke."

"The police should be guarding you," Doc said. "Why aren’t they?"

Rensance shrugged. "They are watching my city apartment. They think I am there. The place has a back door, which I used. I came here to make my payment. I was ordered to do that."

"Do you know who is behind this?"

"A man named Ted Parks," Rensance said.

LIKE a bullet following an explosion, there was an echo to Rensance’s statement. A yell. Not Ted Parks, voice. Not the voices of any of Doc’s aids.

It said, "Pat and Jen are here! Help me quick!"

It came from the vicinity of the gate lodge.

Doc Savage was watching Rensance as the cry came. There was expression on the man’s face suddenly, the kind of an expression that would follow the jab of a needle.

Doc swung to Rensance, fastened a hand on the man’s arm. "You know that voice. Who is it?"

Rensance whitened rapidly, but said nothing.

"Who is it?" Doc demanded.

"The man I paid the money to—I think," Rensance said.

There had been delay, a moment or two. It angered the bronze man. He seized Rensance, propelled the man to the nearest window.

Doc put crashing volume in his voice. "Monk, the rest of you! Be careful! That was a trick!"

He got an answer, a quick whistle from someone. A dash-dot-dash in code. The letter "K." Short for okay. They had heard his shout.

Gripping Rensance’s arm, he hauled the man out of the house almost bodily. He left by a window because he was not sure now but that the doors might be watched. He began running.

Rensance stumbled frequently; he had trouble with his going. The man was out of shape, his arm soft enough under Doc’s fingers to be filled with water.

But they met no one until they neared the gate lodge, where Doc stopped.

The bronze man called, in Mayan so no one but his aids would understand, "You fellows identify yourselves. Do not use English."

Monk’s squeaky voice came from the left. "Long Tom is with me," the homely chemist said. Johnny was to the right, Renny to the left. Ted Parks was with Renny.

"Have you found anyone?" Doc called in Mayan.

They had not.

"Monk, come here," Doc said. "Do not move. Do not make a sound."

Monk approached. The bronze man turned Rensance over to the chemist, saying, "Watch him."

Moving away, the bronze man found a spot to listen. There was no sound but the night insects, distant traffic, a train very far away. Then, off to the right, he heard what the ears of the others had not caught: A man going away.

Doc called in Mayan, "Get away from the lodge. Get at least a hundred yards away. Come here first, though."

They joined him—Renny, Monk, Long Tom and Johnny. He gave them a flask. Ted Parks also joined them.

"Rub this liquid over your faces and hands," he said. "Sprinkle it on your clothing."

Renny unscrewed the flask cap. He smelled the contents. He gagged. "Holy cow!" he gasped. "Worse than a skunk."

"Rub it on yourselves," Doc said. "Rub it on Rensance, too."

He poured some of the stuff in his own palm, smeared it over his exposed skin, letting drops spill on his clothing, as he ran in the direction of the footsteps he had heard.

The stuff stung his skin. It smelled. The odor was nothing like the one Renny had attributed to it—skunk—but it was as distinctive in its way. He was careful to keep it out of his eyes. Once he heard Monk bleat out in involuntary agony behind him and decided the homely chemist had not been as careful about his eyes. Doc had forgotten to warn them.

He heard, shortly, a motorcycle engine start up, then roar away. He got one glimpse of the machine, its headlight, a spike of white which it pursued. It was far away. He fired once, using one of the guns he had captured. It was too dark to see gun sights. He missed it. It was one of the few times in his career that he had used a gun on a person and—he thought of this grimly—the first time he had ever missed with a shot when it was vitally important that he should not miss.

He went back to the others, and Monk said, "I’m blind! I’m as blind as a bat."

"He means in one eye," Renny amended.

"It will not last," Doc said.

"It won’t, huh?" Monk was relieved. "It’s sure hell while it does last."

Long Tom said, "Doc, that fellow yelled out that he had Jen and Pat. Why did he do that?"

"Possibly to decoy you away from the lodge," the bronze man said grimly.

Monk began, "Say, what was that stuff we rubbed—" He stopped. "To get us away from the lodge? Say—" He whirled and headed for the gate lodge.

"Easy!" Doc warned.

They went to the lodge. The bronze man used a flashlight, first on the lodge exterior. All windows, both doors, were closed.

ASTOUNDED, they watched Doc’s actions. Watched him go to first one window, then another, and explore inside the rooms with the flashlight beam. They saw his face go grim, and they came to his side when he gestured.

They looked through the window at the men motionless on the floor. The prisoners they had left there. All four of them, still tied.

And now quite dead!

They stared at the semi-transparent box, which might have been made of cellophane, which stood on the floor inside the window. Stared until their eyeballs seemed to grow cold.

Doc made a slight, but grim, noise and went to the door.

Ted Parks gripped his arm.

"Wait," Parks said hoarsely. "I’ll go in."

"This is not necessary," Doc told him. "This liquid smeared on our faces, and clothing will protect us."

Parks was trembling. "We can’t be sure. I’ll go in. I am responsible for the existence of this horrible thing. If it kills me—"

He opened the door, entered, then closed the door behind him.

"I’ll be superamalgamated," Renny said thoughtfully. "I believe that took nerve."

Parks struck a match. He found a newspaper, set fire to it. They watched him, growing more puzzled. Parks walked around the room several times, holding the newspaper like a torch. The paper burned. He fired another.

With this blazing torch, he got down on the floor, crawled around. He poked his torch under the tables, the chairs. He got up and poked it up against the windows. All the time, his eyes seemed to be straining, seeking something that he was not finding.

Once he dodged back wildly, and they saw that his face was like greased ivory under the smeared liquid. But he got control of himself. He went on sticking his torch into various places.

"Holy cow!" Renny said.

Later, Parks opened the door.

"Everything is all right," he said.

Then he quietly fainted.

Chapter XIII. THE PIGEON

LONG TOM ROBERTS, the electrical expert, finished examining the dead men.

"It’s another case of the invisible-box death," he said. "But farther than that, you can’t prove a thing by me."

The tension, the horror, made him speak barely above a whisper.

Monk Mayfair took off his coat and put it on the floor. He placed the semi-transparent box on the coat, after thumping and examining the box and saying, "If this isn’t cellophane, I’ll eat it." He then tied the various extremities of the coat together to make a package. Then he searched through the lodge and came back with an old gunny sack. He put coat and box in the sack and tied the sack mouth.

"This is one box that won’t get away from anybody," he declared.

Ted Parks stared at Doc Savage. "We cannot report these deaths. The police will insist you are responsible."

The bronze man nodded. "Do you know where the murderers’ headquarters is?" he asked.

"I know one place," Parks said. He gave an address.

"No good," Doc told him.

"Why not?"

"That is where Monk, Renny, Long Tom and Johnny were being held," Doc explained. "It was a hide-out for a part of the gang. We want their real headquarters, assuming that there is where Ham, Pat, Jen and Uncle Joe Morgan will be held."

Parks said miserably, "I cannot give you any idea where the rest of your associates are."

Rensance said in a terrorized voice, "Perhaps they are dead."

"Shut up!" Monk snarled at him. "I don’t like that kind of talk."

Renny blocked out his big fists and loomed over Rensance. "You might know more than you’ve told us, fellow. I’ve got a notion to work you over to see what comes out." Emotion made the huge engineer’s deep voice have the sound of a truck on a bridge of loose boards.

Rensance trembled helplessly. "I’ve told you all I know."

"Yeah?" Renny grabbed him. "You sure?"

Doc said, "He seems to be telling the truth."

"We have to find Pat and Ham and the Bridges girl," Renny rumbled. "That old Morgan fellow, too."

Renny’s voice was not stable. He was, if they stood there much longer, going to fly to pieces.

"Come up to Rensance’s house," Doc said quietly.

Walking back to the mansion eased the tension somewhat. Ted Parks had difficult going. He had recovered quickly from his faint. But he was weak, and several times both knees buckled simultaneously, although he did not fall.

Parks was evidently thinking, too. When they were in the big house, he faced them.

"This Bridges girl," Parks said. "What does she look like?"

Monk described her. Monk’s memory for feminine pulchritude was dependable. The description of pretty Jen Bridges was almost photographic.

Ted Parks heard the description to its end.

"That is my sister," he said.

And he quietly fainted again.

Doc Savage examined Parks, and his nod to the others indicated that this faint was no more serious than the other one.

"Rensance," Doc said, "where is that pigeon?"

"I’ll get it," said Rensance nervously.

"Yeah, and I’ll go with you," Renny told him, making no secret of his distrust.

The two of them went away, brought back the pigeon. It was an ordinary carrier pigeon in a not-too-clean cage of wire. A parrot cage. As they carried the cage, the pigeon flapped its wings a little to balance itself. When the cage stood quiet on the table, the bird eyed them placidly, then closed its eyes and seemed to sleep.

"Tame cuss," Long Tom commented.

Doc indicated the bird. "Long Tom, Renny, Monk and Johnny—all of you stay here the rest of the night and guard that bird."

"Guard it?" Long Tom said, surprised.

"Do not let it get away," Doc told him. "If it does, it will mean losing the only chance I can see of locating Pat and Ham and the others."

They were impressed.

"Rensance will stay with you," Doc added.

"And I’ll guard him," Renny declared.

Doc turned to Rensance. "Have you a car?"

"My limousine," the wealthy extortion victim replied. "You may use it."

Doc picked up the unconscious form of Ted Parks. "Show me the car," he directed.

They walked through the house to a connecting garage. Monk trailed. He was in the throes of puzzled surprise. "So Jen Bridges is really Parks’ sister," he said. "Now, I wonder why she told us her name was Bridges. I guess Parks is the brother she was so worried about. But why’d she tell us he had been seized? Wonder if he was seized?"

Doc made no comment.

THE night was darker when Doc drove out of the estate with Ted Parks limp on the seat of the limousine beside him. Lightning that was not heat lightning promised rain in the south. He drove rapidly.

He had noticed a fountain pen in Parks’ pocket. He used the ink from this to cover his face as best he could, darkening it. There had been a chauffeur’s topcoat and uniform cap hanging on a nail in the garage. Both articles were very old, but he had brought them. He put them on. The cap was too small; he had to rip it up the back to give it a resemblance of a fit.

By that time, Parks had regained consciousness.

"Feel better?" Doc asked.

"Jen," Parks said hoarsely. "So she got mixed up in this. I was afraid she would."

The bronze man drove at a sedate speed, joining traffic on a boulevard.

He said, "She came to us, gave the false name and said you had been seized."

"Trying to help me," Ted Parks muttered. "I might have known she would do something like that after she found out I had taken the fake name of Bridges."

"You went under an assumed name?"

"After the murders began, yes. Jen found it out. Her name is not Jen, incidentally. That is, her first name isn’t Jen. She is Susan Eugenica Parks. I guess the Eugenica gave her the nickname of Jen." Parks considered for a moment. "I telephoned her to bring me some clothing, and she telephoned back to the number and found out I was using the name of Bridges. She demanded to know why. I wouldn’t tell her, naturally. She got the idea I was in trouble. Which I was."

"And she ended up by coming to me for help," Doc said.

Parks nodded. "She evidently did that when she found I had disappeared from the place I was staying under the name of Bridges. That must have made her distraught."

Doc asked, "Where were you staying as Bridges?"

Parks told him, naming street and number. A walk-up on Fifty-fifth Street, on the wrong side of Broadway. The place where one of the invisible-box victims had been found.

Parks must have read Doc Savage’s thoughts.

"I know a dead man was found there," Parks said. "That was their first direct effort to frame you. Before that, it had been indirect."

"What did you do after you left there?"

Parks became eager to explain. "A man was watching the place, so I trailed him. I was trying to find out who was behind the sinister thing. I trailed this fellow here and there. As a matter of fact, that was all I did. I didn’t learn anything. I finally became desperate, decided to grab a bunch of them and scare them into telling me what they knew."

"You think those men back in the gatekeeper’s lodge knew the identity of the man behind what is happening?"

"I’m sure of it."

"Most of them seemed to think it is me," Doc said.

"They were deceived."

"These men did not think it was me?"

"No, they knew who it actually is," Parks insisted. "Else, why do you think they were killed?"

ANDREW BLODGETT MONK MAYFAIR was a peculiar fellow. As ugly as a nightmare in a thunderstorm, he actually loved beauty, but was ashamed to indulge publicly. He had a penthouse-laboratory in the Wall Street district—where no one lived, except a few eccentric captains of finance—where he had turned himself loose. Ham Brooks called the place a "plush-lined monkey’s nest," which was not an inept descriptive.

Doc Savage went to this laboratory. At the hour of night, the building was deserted. To get to Monk’s perch in the clouds above the money mart, you opened what looked like a rusty freight door and found a fine gilt elevator, all private. So it was not hard to arrive unnoticed.

Doc removed his coat, drew on a set of rubber gloves, an all-enveloping jacket, and prepared to don a germproof mask. "You will help," he told Parks.

"What are you going to do?"

"Prepare cultures of some germ which will affect a man quickly, but which can be cured by use of the proper serum," Doc explained. "The disease also needs to be contagious."

"I still don’t get it?" Parks was frowning.

Doc arranged microscope slides before a case in which Monk kept germ cultures. "We want to give someone a quick, violent, perhaps fatal, disease," he said.

"How will it be carried?"

"On that pigeon," Doc told him. "Or in a container attached to the pigeon, which will be so arranged that it will scatter the germs over the victim when the container is opened. A small container, necessarily."

Parks began to get the idea. "How about a toxic poison? I think I remember a place where we could get some bushmaster venom. There’s few things more fatal."

"Where did you learn about bushmaster venom being available in New York?"

"Fellow in South America told me about shipping it to a firm up here."

"You were in South America long?"

"Four years."

Doc said, "We do not want venom. We want germs! Let us see what Monk has available."

Parks joined the bronze man. He was startled by the completeness of Monk’s laboratory.

"Why, this is amazing!" he exploded. "I never had anything in his section as complete as he has right here devoted to research in bacteriology and toxicology."

Doc made no comment. His own laboratory was many times more complete than this. He watched Parks work and knew that he had been guessing correctly about the young man. Parks had great skill.

THE sun came up with a shower of gold on the hills of Westchester and was cast back in jeweled reflections from the windows of the Rensance home.

Doc sat in the library and wrote with a pen:

When you opened this message, you released enough germs—tularemia, dengue fever, sleeping sickness—to kill you and everyone you come in contact with. So consider yourself paid off for trying to frame me.

Ted Parks.

"Parks, you think that looks enough like your printing? Or do you want to copy it off yourself?" Doc asked.

"I print about like that," Parks said.

Doc placed the message in the trick container they had rigged. It would release a shower of germs, and the germs were genuine. He attached the container to the pigeon.

He freed the pigeon. It flapped away in the morning sun, climbing, setting out to the east.

"Holy cow!" Renny rumbled. "The pigeon will give these guys something they’ll have to get a serum to combat. That the idea?"

Doc nodded. "And the serums for those diseases cannot be had everywhere. We will watch the places where they are distributed, or have them watched, and will check everyone who needs serums for treating those diseases."

Long Tom came in. "Three telephone lines are all that come into the house," he said. "I have them rigged up on separate instruments."

"That is good," Doc said. "You and Johnny and Renny get on the telephones. Start calling chemists and pharmaceutical concerns dealing in remedies for tularemia, dengue fever, and sleeping sickness."

Long Tom nodded. "You want particularly to be notified of anybody who wants treatment for all three."

"They might get one serum at one place and go to another for the other," Doc said. "So do not depend too much on their asking for all three serums at the same spot."

The electrical expert nodded. He and Renny and Johnny became busy on the telephones.

After that, there was no sound but the quietly efficient murmur of their voices and the clicking of receiver hooks as they recalled operators to the lines.

Monk had no telephone. He paced nervously, uneasy because he had nothing to do; he felt he was not accomplishing anything.

"Doc, where’s my pig, Habeas Corpus?" he demanded.

"At headquarters. Do not dare go get the animal. Police will be watching the place."

"Yeah, I guess they will at that. What about Chemistry—poor Ham’s pet?"

"Chemistry," Doc said, "seems to have been with Ham when he was grabbed. No one has seen anything of the chimp since."

Chapter XIV. THE SKEPTIC

THE hands on a bank clock stood at the hour of four in the afternoon when Doc Savage walked into a telephone booth in a drugstore and called New York police headquarters. He got Lieutenant Blosser.

"Yes," said Blosser.

It was the father.

Doc said, "Savage speaking. Do you still feel I am guilty of these invisible-box murders?"

The elder Blosser hesitated. "I’m afraid so," he said.

"Would you care to be shown differently?"

"I sure would," Blosser said instantly.

Doc told him. "Bring your son. Come to Westchester county." He gave an address. "Enter the place. I will contact you there. But you must come alone."

"Why alone?"

"We are about to try to clear all this up," Doc Savage informed him. "It may be dangerous, and certainly it is no job for a bulky force of men. Four of my associates are free and will help me. Also Ted Parks. So come alone. Two more men will not make our group too bulky."

"My son and I will be there alone."

"You promise that you will bring no outsiders?"

"No outsiders." Blosser then repeated the address for certainty.

"That is right," Doc told him.

That ended the telephone conversation.

Doc had a bite to eat, then approached the address he had given Blosser as a meeting place. The spot was another store. This one sold cigars. A small candy shop was located diagonally across the street; and, from this, a view could be had of the cigar store’s interior. Doc took a booth, ordered a soda and waited.

He saw both Blossers arrive and enter the cigar store. Doc went to a telephone, called the cigar store.

"Will you page Lieutenant Blosser?" he said.

To the elder Blosser, who came to the telephone, he said, "I wonder if you would drop down the street five blocks turn to the right one block and wait on the corner?"

"What’s the idea?" Blosser demanded.

"I will meet you there," Doc said. He hung up.

Then he watched the Blossers leave the cigar store. He stepped out on the sidewalk and watched them enter their car. He saw no visible evidence that they had given a signal, or that other police were with them.

So he met them on the corner he had indicated.

Both Blossers seemed a little suspicious.

Doc told them about the pigeon, about the germs, about the serums and antidotes for the germs which must be obtained in a hurry and could only be obtained at a few spots.

"Why, that’s a slick one!" Blosser exclaimed. "Did it get results?"

"Come on," Doc Savage said, "and we will see."

HAZE of twilight was gathering like fog among the trees as they drove their cars into roadside brush and unloaded. The spot was a remote one as far as human habitation was concerned. It was not far, though, in miles from the city.

Long Tom and Johnny were with the Blossers and Doc Savage. They had driven in a second car. The Blossers and Doc had ridden alone in the police machine, which was a big sedan of the type used by the detective bureau. It had no identification on the outside to show it was an official car, other than license plates, but it was equipped with radio and weapons.

"Need guns?" young Blosser asked.

"Probably," Long Tom told him.

They moved a few yards into intense undergrowth. Monk Mayfair appeared alongside them with the startling abruptness of a jungle denizen.

"Hello, there," Blosser said.

Monk frowned at him. He had not liked Lieutenant Blosser in the beginning, and he did not like him now. "It was Doc’s idea to ring you in, you pest," Monk told him.

Lieutenant Blosser looked startled. He was not accustomed to such blunt talk.

Doc asked, "What is the situation, Monk?"

"Seems all right," Monk told him. "As you know, two guys showed up and bought some of the necessary serum, and we trailed them."

Lieutenant Blosser said, "Just because a man bought serum, I don’t see how you could be sure—"

"They bought treatment for tularemia, dengue fever and sleeping sickness—all three. It’s not likely anybody but these rats would need all three at the same time. Those three diseases don’t commonly run together."

Blosser was impressed. "I see."

Monk turned back to Doc. "The chemical house managed to hold these guys by telling them they had to get the serum and it would take half an hour, then the firm got in touch with us. We trailed the men to"—he gestured into the woods—"that house in there. They’re all there. It’s their headquarters."

Doc addressed Blosser. "We are going to close in on the place. Are you with us?"

"Absolutely!" Blosser declared.

The bronze man produced a case closed with a zipper, opened it and handed out bottles containing liquid.

"Smear this stuff on your faces," he said. "Never mind the smell."

"It goes good in the eyes, too," Monk said dryly.

Lieutenant Blosser stared at the bottle, puzzled. "What does this do?"

"Keeps the invisible-box death away from you," Monk informed him.

Blosser gaped. "I don’t believe that!"

Monk snorted.

"How does it keep it away?" Blosser demanded.

Monk ignored him.

Blosser took a step forward, grabbed Monk’s arm, and rasped, "Look here! If you fellows know—"

Monk brought his arm slowly down and around and twisted out of Blosser’s fingers. "You put your hands on me again," Monk told him, "and I’ll pull them off and stuff them in your ears."

Blosser retreated hastily. In Blosser’s private opinion, Monk Mayfair was about as safe as a can of nitro-glycerin. Which was what Monk wanted him to think.

Meekly, Blosser smeared the stuff over his face and hands. He sprinkled it on his clothing. His father did likewise.

Doc Savage led the way, and they worked through the trees and brush.

Blosser touched Doc’s arm, asked, "You think your friends—Ham, the two girls and Morgan—are alive?"

"Probably."

"What makes you think that?"

"The man behind this has gone to elaborate pains to build up the impression that I am masterminding the thing," Doc explained patiently. "He has given the impression that my aids are not to be killed for that reason. That was part of the build-up. He cannot murder them now, without destroying the impression he has so painstakingly created."

"That’s logical," Blosser admitted.

THE house was large and ancient, partly of stone, the rest of wood. It was not a mansion; it might have seen the days when it was one, but that had been at least fifty years ago. The north wing needed a new roof.

Long Tom and Johnny and Monk were joined by big-fisted Renny, who had been watching the place at close range with young Ted Parks.

The Blossers eyed Parks intently. The younger Blosser gripped Parks’ arm.

"You are under arrest," Blosser said, "for suspicion of complicity with Doc Savage in these murders. There is a great deal of evidence pointing at you as one of the killers, as well as at Doc Savage."

Doc was displeased. "I thought you two officers came here to learn the truth."

"And make arrests," Blosser told him coldly. "I have just made one of them."

Without a word, Monk belted young Blosser on the jaw with his fist. Blosser was out for a moment, then sat up groggily, gasping. "What . . . what—"

"That," Monk told him, "was the cancellation of your arrest. You came along to observe, not start asserting authority."

Blosser subsided, concerned with the ache in his jaw, with the grim air of Doc and the others. The darkness was getting more intense. And Doc and the rest seemed to be doing nothing but waiting.

Finally, "Use that chemical on your skins again," Doc said. "Then spread out. We will approach the house from four directions. No one make any noise. Start getting inside, and try to find the prisoners. That is the first job."

The Blossers watched the others fade away into the darkness.

"You stay with me," Doc told them.

"What about this Parks?" demanded the younger Blosser. "You trust him?"

"Completely," Doc said. "He risked his life last night to make sure we were safe."

"Where does he hook into this?"

"Parks developed this thing you have been calling the invisible death," Doc told him.

Young Blosser literally lifted off the ground. "What? Great grief. And you let him run around loose?"

"Quiet!" Doc said. "Here is the house."

The Blossers became reluctantly silent.

Doc added, "My men are completely armed and protected. We will go ahead. You follow."

Doc went forward quietly, drawing a species of hood over his face, a thing that was something like the chain mesh hoods worn by medieval knights. This one was lighter, and the face-piece was of transparent plastic which would arrest any slug carrying less than a thousand foot-pounds of energy. That included most revolver bullets.

He reached a side door, waited. They had outlined a plan of action earlier.

Rensance was to knock on the front door. Rensance had been concealed in the darkness nearby, had not come out while the Blossers were being introduced to the situation. Rensance was embarrassed about having paid extortion; he was anxious to redeem himself. His courage had returned.

Knuckles thundered on the front door. The sound was so loud that the Blossers jumped.

Rensance bellowed, "Quick! Let me in! Open up! I’ve had to kill one of Doc Savage’s men!"

Doc shot out a hand and grabbed young Blosser just as the officer was bent on charging around to the front.

"Trick," Doc whispered. "Quiet!"

Rensance was a good actor. He squalled, "Please let me in! I’ve got one of Savage’s men here! He’s dead!"

Doc knew the situation: Rensance at the front door. Monk sprawled out on the walk. Monk with red ink wet on his face. With more red ink in his mouth, so that he could gurgle realistically at the psychological moment. With a knife haft appearing to protrude from his chest. A piece of fakery.

When enough commotion was going on in front to have distracted attention, Doc reached for the doorknob.

The door was not locked, and he went in, cautiously, on toes. The Blossers followed him. No one seemed to be in front of them.

Doc whispered, "Careful about rubbing off that liquid you smeared on yourselves. That is all that stands between you and death!"

The elder Blosser halted abruptly. "You mean if men come here who haven’t that stuff on them, they will be in danger?"

Doc said, "They will be facing fairly certain death."

Blosser made a sound that was horror. He wheeled and, before Doc could stop him, leaped back to the rear door.

"Stay back, men!" Blosser bellowed into the night. "There’s danger here! Stay back! Don’t raid the place!"

The trees tossed echoes of his yell back in the darkness.

Then silence for a moment.

"Who were you yelling to?" Doc asked.

There was something bitter, condemning, in the bronze man’s tone which shocked Blosser.

"My men," he said. "Policemen."

"I thought you said you were not bringing officers," Doc said.

"I know." Blosser was miserable. "I was not taking any chances, that’s all."

"That precaution," Doc told him, "quite possibly may result in all of us losing our lives."

THE bronze man was as near as he ever came to being violently enraged. He seized young Blosser and slammed him across the room. The officer ended up sprawling in a corner. Doc shoved the older Blosser toward the same spot.

He said, "Stay there!" and there was no doubt but that he meant it.

He lunged across the room, tried a door. It was locked. He retreated, brought an arm back, flung an explosive grenade. It exploded against the door like a Fourth-of-July torpedo. The door, through some freak of concussion-tortured air, jumped outward instead of inward. It floated around like a big leaf in the flame and smoke and splinters.

Doc walked through the wreckage.

Monk yelled, "Come on, boys! Joe, Jerry, Fred—you take the left. Half a dozen of you head for the upstairs. The rest of you come with me! Don’t crowd!"

Which was typical of Monk in a fight. Sounding like an army. Actually, he was alone.

No Joe, Jerry and Fred. No half dozen to go upstairs. Only Monk. Roaring and bellowing and having the time of his life.

The fight was on, now. And no one had been taken very much by surprise, thanks to the warning Blosser had been forced to shout to the police.

Doc realized both Blossers were following him. Father and son, close together. He whirled on them. And the father snapped, "All right, we made a mistake. So we’ll do our part of this fighting."

Monk was yelling to more imaginary men.

At the other end of the house, Renny had started doing the same thing. He was telling his hypothetical army to take the basement.

Some one of the defenders, impressed, bellowed, "Get rid of the prisoners down there!"

That meant the captives were in the basement. Doc headed for the stairs going down. No great ingenuity was exercised in houses of this size, fifty years ago; so he knew about where the basement steps should be. They were there.

He went down. Lieutenant Blosser and his father trailed close on his heels. Their feet was a hard drumming on the steps.

They were shot at, once at the foot of the stairs. The bullet made the side of Doc’s left hip ache with a glancing blow, went on, and chipped the bone in young Blosser’s left leg. Blosser fell silently, trying to save himself, and upset Doc. They sprawled on the basement floor.

The man with the gun fired again. That one was a complete miss. Doc reached him, chopped down on the gun arm with a fist. Blosser pounced on the gun when it fell.

"Ham!" Doc called.

Ham’s voice answered immediately, "Watch out, Doc! They’re turning loose those infernal mosquitoes!"

Ham called from the coal bin, it developed. Doc went into the place with a flashlight. Three very black, indignant figures proved to be Ham, Pat and Jen Bridges.

"Where are the mosquitoes?" Doc demanded.

"Next door—their workshop," Ham yelled.

Doc told the Blossers, "Untie these people!" and went next door.

HE found a room crowded with makeshift chemical apparatus and numerous cases of fine bronze mesh wire. The cases contained mosquitoes of rather unusual species, large and colored, rather like hornets. Large mosquitoes, but not giants. New Jersey has them as big. These were a tropical variety, however.

A man was opening a window. Obviously, his idea was to escape by that route.

Half a dozen of the cages were open, with mosquitoes escaping!

The man did not see Doc until the bronze man reached him. Then he half turned. Doc slugged him! Then Doc picked the fellow up, pitched him out through the basement window.

Chemicals were plainly marked. He picked up three jugs that were inflammable in content, smashed them on the walls. Then he touched a match, and flames crawled like red animals.

He went back and got the prisoners, who were now loose.

"Climb out through the window," he said, "and run for it."

The window was actually a coal chute. They clambered atop the coal, worked out through the chute. Doc came last. It was a tight fit.

There was fighting in the house. Not much. One gun crashing.

Doc lifted his voice.

"Run for it," he shouted. "That ‘invisible-box’ death is loose!"

He bellowed in Mayan, so that his men would understand and not be likely to mistake his voice for another.

Monk, Renny and the others piled out through windows.

Inside, a voice began bleating in terror.

"Help me!" it screamed.

Monk said, "That’s old Uncle Joe Morgan! I’m going in after him."

The homely chemist dived back inside the house. He was not gone long. He had Uncle Joe Morgan over his shoulder when he reappeared. Uncle Joe was tied hand and foot.

Doc said, "You fellows have flares. Light them and scatter them. Blosser, bring in your policemen. As that house burns, those fellows will have to come out. They may have to come out sooner to escape the mosquitoes. Apparently, we have them cornered."

Chapter XV. WATCH

LIEUTENANT BLOSSER, the father—both father and son were lieutenants, which made it confusing—looked tired when he walked into Doc Savage’s office at ten o’clock the following morning.

He carried Ham’s pet chimp, Chemistry. He deposited the animal on a table.

"A policeman found him hiding out in the woods," he said.

Monk scowled at the chimp. "Now I don’t like policemen," he said. "Why’d you have to find that blasted critter?"

Ham snorted.

Pat Savage, Jen Bridges, Uncle Joe Morgan, Long Tom, Renny and Johnny were in the library. All of them looked very tired, but much relieved.

"Where is Mr. Savage?" asked the elder Blosser.

"He and Ted Parks will be here soon," Monk explained. "For some reason, Doc wanted us all together."

Blosser nodded. "The police department owes you an explanation." He fumbled in a pocket, and produced a packet—an article inclosed in waxed paper. He unrolled this. It was a glovelike gadget with thick fingertips. It was made of some kind of composition similar to rubber, but more sticky.

"This," said Blosser, "explains how Doc Savage’s fingerprints got in the wrong places."

Monk came over and eyed the glove affair. "Doc’s fingerprints on that?" he demanded.

"Worked into the plastic with a system of photo-engraving," Blosser said. "At least, that’s what the police expert tells me. Says he just got copies of Doc’s fingerprints and made up these things. The plastic is impregnated with an oil similar to the oil on human skin. It wasn’t exact, of course. But it had us fooled."

Monk said, "He was a scientific cuss, the guy behind this."

Blosser nodded. "The fellow must have been."

"Take those death-dealing mosquitoes," Monk grunted.

Blosser hesitated. "You know, the department is a little dubious about those mosquitoes being able to kill a man instantly."

Monk shook his head. "They didn’t kill him instantly. It took a few minutes, maybe more than an hour."

"But those men murdered in the gatekeepers’ lodge at the Rensance estate—"

"Were murdered with big injections of the poison," Monk said. "Later examination of the bodies will show that."

"But there were mosquitoes loose in the lodge."

"Sure, on the chance we would barge in and get bit."

Blosser was still doubtful. "The department experts," he said, "do not entirely believe the mosquito story."

"Oh, it’s simple enough," Monk told him. "Parks was working on the problem of disease-carrying mosquitoes. He was tackling it from the angle of determining just what poisons or germs mosquitoes could carry in their systems without themselves dying. He found out mosquitoes could carry a poison that would kill a man, and not leave much trace."

Blosser strode to the window. He glanced at Jen, hesitated.

"I don’t mind saying Parks isn’t clear yet!" he finally said.

Jen became pale.

"Nonsense!" Ham snapped, and got a grateful look from Jen which Monk immediately wished he had received.

"The murderer simply got a lot of mosquitoes and doped them up with poison," Ham said. "Then he put them in a cellophane box, sent them to the men he wanted to kill—the men who wouldn’t pay the sums he asked. That was all there was to it."

"Yes, but the boxes disappeared," Blosser said.

"They couldn’t have."

"One of our policemen had one of them which vanished."

"He lost it."

Blosser became indignant. "He did not!"

"All right, I’ll prove that the boxes are ordinary cellophane," Ham snapped. "Monk had one of them wrapped up in his coat and shoved in a gunny sack. He turned it over to me to take care of. I’ve got it right there in the corner. I looked at it not thirty minutes ago, and the box was still there."

"Show me," Blosser challenged.

Ham got the gunny sack, emptied it and became gap-jawed when there was no box.

Monk Mayfair burst into a howl of laughter. "You should see that face of yours!" he told Ham. "It’s even dumber than usual."

"What became of it?" Ham asked vacantly.

"Those boxes were made of stuff that just evaporated," Monk said. "In other words, it wasn’t cellophane. It was a colorless semi-transparent composition which was volatile at room temperatures. Or you might call it soluble in air. You know these capsules you take medicine in—you know how they dissolve in water? Well, this stuff dissolved in air."

Lieutenant Blosser interrupted. "If I hadn’t seen some of the things Doc Savage has developed in the line of scientific gadgets, I wouldn’t believe that."

Monk chuckled. "I think the smartest thing Doc did was advertise for a man who had slept three weeks, a radium miner, and the addresses of monkey purchasers."

Blosser was startled. "I still don’t understand that."

"Why, Doc did that to tip off the gang that he knew what was going on, but at the same time not give them the idea he knew too much," Monk explained. "This poison is a development of the stuff—germs or whatever they are—that causes sleeping sickness. Any man who had slept three weeks would have to have sleeping sickness of some kind. As soon as Doc advertised for a man who had slept that long, the villains knew he was on the sleeping-sickness trail."

"And the monkeys?"

"Monkeys are used by scientists in experiments with the effects of sleeping sickness and other similar diseases," Monk told the officer. "That was simply another tip-off for the villains."

"Savage wanted them to get scared?"

"Sure. So they’d do something desperate enough to give him a line on them. They did. They began grabbing us, so we couldn’t help Doc investigate."

"I see."

Jen Bridges spoke up. "The radium miner—what was he for?"

"That," Monk confessed, "is one I haven’t figured out."

A FEW minutes later, when Doc Savage arrived, Monk put the query to the bronze man.

"Hey, Doc, we can’t figure out why the radium miner."

Doc Savage moved to the middle of the room. Parks took a position near the door.

Doc said, "The radium miner? Why, that was a warning to the man behind the extortion murders that we had a clue to his identity. It was intended to excite the fellow."

"How?"

"Because of the method he was using occasionally to signal his men."

Blosser shook his head. "I don’t get it."

Doc nodded to Parks. Parks stepped outside, and came back bearing a long box of an affair which had at one end a hood that fitted over a man’s head, after the fashion of the light-cloth on a photographer’s studio camera.

Long Tom recognized the gadget instantly.

"A homemade fluoroscopic scanner," he declared.

Blosser stared. "A what?"

"It is used to locate objects giving off radioactive emanations, such as X rays."

"Or like radium?"

"Or like radium," Long Tom agreed.

Blosser lost his control and sprang to his feet. "Look here, I’m getting tired of all this talk about scientific gadgets!" he howled. "We want results. Commissioner Strance and District Attorney Einsflagen want to know who the man behind this was. None of our prisoners will admit knowing. Who was he?"

"The man behind it," Doc Savage said, "was the one who used his watch to signal his men."

"Huh?"

Doc said patiently, "In the very beginning of this thing, the brains of the organization had to signal his men to make an attempt on my life, and prepare a trap for me. We were watching him; so he was not able to talk to anyone, write a message, use a radio, or speak over a telephone. He had surmised such a situation might develop, and he was prepared for it. This fellow liked gadgets. So he had rigged up the device for spotting radioactive emanations. He had put a bit of radioactive mineral inside his watchcase. The watchcase was lead-covered. Lead will stop radium emanations of small power, such as these were."

Blosser understood that. "You mean he just opened and shut his watchcase to make dots and dashes, and somebody across the street, or somewhere nearby, watched through that fluoroscopic scanner and read it."

"A trifle fantastic," Doc admitted, "but true. As I reminded you, this mastermind is rather silly on the subject of chemical and mechanical gadgets."

"Who is he?"

Doc turned to Ted Parks. "Parks, who is one of the cleverest men you know along that line? Who was your assistant for some time in your experiments?"

"Why, Uncle Joe Morgan, there," Parks said. "I went to South America on Uncle Joe’s small boat, and he helped me with the work on mosquitoes—"

Doc said, "Morgan, let us see your watch."

Uncle Joe Morgan cursed terribly, sprang to his feet. They did not, however, find out what wild thing he contemplated doing because one of his ankles was tied to his chair, and he fell flat on his face.

It was a simple matter for Monk to stroll over and sit on the back of Uncle Joe’s neck.

Monk looked at the chimp, Chemistry, with an expression that was almost approving.

"Now I know what has been tying tin cans and ugly pictures to my hog," he said. "Ham, you’ve taught that danged what-is-it of yours to tie knots."

Doc removed the watch from Uncle Joe Morgan’s pocket and tossed it to Blosser without a word. Blosser examined the watch. He held it in front of the contrivance for making radioactive emanations visible to the unaided eye.

"Uncle Joe it is, all right," he said. "He sure set a trail to you, Doc, and to Ted Parks when Parks threatened his chance to get all that money."

After that, he went to the door and yelled at a policeman posted in the hall.

"Fetch a pair of handcuffs in here, Andy," he said.

THE END