TOM SWIFT AND HIS

AIRLINE EXPRESS

or

From Ocean to Ocean by Daylight

by

VICTOR APPLETON

WHITMAN PUBLISHING CO.

Racine, Wis. Poughkeepsie, N. Y.

Copyright, 1926, by

GROSSET & DUNLAP, Inc.

New York, N. Y.

ALL RIGHTS RESERVED

Printed in U. S. A.

CONTENTS

Tom Swift and His Airline Express

CHAPTER I
SOMETHING QUEER

“Ours is sure a great plant!” murmured Tom Swift to himself, with justifiable pride. “It would be a credit to anybody. No wonder dad loves it, and so do I. Yes, it sure is a great plant! We’ve had our troubles—our ups and downs—and our enemies have tried their hardest to wipe it out.”

Darkness was slowly gathering over the landscape, shrouding in velvety black the trees which were faintly stirring in the summer breeze. Tom, following an old-time cowpath across the green meadow on his way home from town, topped a little rise and caught a glimpse of the high board fence surrounding the Swift Construction Company’s plant which he and his father had built up after many years of hard work.

Tom paused for a moment to trace, in the fast-gathering shadows of the night, the outlines of the various buildings—the foundry, the wood-working mill, the electrical shop, the hangars where many types of aircraft were housed.

From some of the tall chimneys faint clouds of smoke arose, for certain of the industries carried on by the Swift Construction Company required that furnaces be kept going day and night.

“A great plant—a wonderful plant!” mused Tom. It gave him a certain sense of pleasure to dwell thus in introspection on the accomplishments of his father and himself. And it buoyed him up for the work in prospect—for Tom Swift had a great plan in mind, a plan so great and daring that, as yet, he had said but little of it even to his father or to Ned Newton, his old chum who was now an officer of the concern.

“But it can be done! I know it can be done!” declared Tom. “And I’m going to do it! I’m going to——”

In his mental energy he had unconsciously spoken the last words in a low voice, but the sight of something just ahead of him in the gathering darkness caused him to break off abruptly and halt suddenly. Concentrating his gaze, Tom Swift looked eagerly at a clump of bushes.

“It’s a man,” murmured Tom Swift. “A man, sure enough, and it isn’t one of our workers, either. None of them would sneak around as he is doing.”

For that described exactly the movements of the stranger of whom Tom had caught sight in the darkness as he approached the big fence which surrounded his plant.

“What’s he up to?” mused Tom. “No good, that’s sure. He wouldn’t sneak along like that if he were on the level.”

Through Tom’s mind flashed remembrances of times when attempts had been made by enemies of himself and his father to fire the plant. To prevent this, and to keep strangers away, a high fence had been erected around the buildings. This fence was protected by wires on the plan of a burglar alarm, so that, no matter at what point the barrier was climbed, a bell would ring in the main office and on an indicator would appear a number to show at what part of the fence an attempt was being made to scale it.

An effort to break down the barrier, or burrow beneath it, would also sound the alarm in like manner. So Tom had no fear that the sneaking stranger, crouching along in the darkness, could get into the midst of the buildings without notice being given.

“But what’s his game?” thought Tom.

Almost at the instant he asked himself this question he saw the man crawl behind a clump of bushes. In the natural course of events the man should have appeared on the other side of the clump. But he did nothing of the sort.

“He may be hiding there,” mused Tom. “Perhaps waiting for a confederate. I’ll just have a closer look at this!”

He advanced boldly toward the bushes. There was nothing between him and the shrubbery, and it was still light enough to see fairly well. Besides, Tom had extraordinarily good eyes. His astonishment can be imagined when, on reaching the bush off which he had not taken his gaze and behind which he had seen the crawling man disappear he found—no one!

“That’s the queerest thing I’ve seen yet!” exclaimed Tom, rubbing his organs of vision.

Standing beside the bush which came about to his shoulders, Tom looked on all sides of it. There was no hollow in the ground, as far as he could make out, no depression and no other clumps of shrubbery and no boulders behind which a man might be hidden. Some distance away there were all of these things in profusion, for the land was wild and uncultivated outside the plant fence. But there was not a hole, boulder, or bush near enough to the one beside which Tom stood to have enabled a man to gain their protection while the young inventor was watching.

“He just crawled back of his bush and then vanished!” said Tom, in a half whisper to himself. “If only I had a flashlight now——” He was startled by hearing some one walking toward him out of the darkness which was now quite dense. “Here he comes!” thought Tom. “Appearing as queerly as he disappeared. Or else it’s one of his confederates.” He could see no one, and his hand clutched something in his pocket that might be used in case he was attacked.

But a moment later, just as Tom’s nerves and muscles were getting tense in anticipation of a struggle, a cheery whistle broke out in the darkness, mingling with the now louder sounds of the footsteps, and Tom, with a cry of relief, called:

“That you, Ned?”

“Sure, old scout!” was the reply. “Oh, there you are!” went on Ned Newton, as he caught sight of Tom at the same moment the young inventor glimpsed his friend and financial manager.

“You’re a bit late,” went on Ned. “I waited for you, and when you didn’t show up I thought I might as well walk in toward town and maybe I’d meet you.”

“Yes, I couldn’t get just what I wanted until I had tried two or three places,” Tom answered. “And then I met a man——”

Ned broke into a laugh.

“What’s the idea?” Tom wanted to know.

“Tell that to Mary!” advised his chum. “She may believe that and then you can tell her another.”

“Whew!” shrilly whistled Tom. “I forgot all about Mary. I promised to call on her to-night.”

“Sure you did,” laughed Ned. “And I’ve got a date with Helen. You said we’d go over together and——”

“Clean forgot it!” broke in Tom. “And I can’t go now. I’ve got something to do.” Quickly he made up his mind to say nothing to Ned of what he had seen until he investigated a little on his own account. “Here, I tell you what to do,” went on Tom. “Go on, keep your date with Helen, but when you get to her house telephone to Mary for me and say I’ll be a little late. Will you?”

“Pull your chestnuts out of the fire? Is that it, Tom? I reminded you myself before supper!” laughed Ned. “Well, I don’t mind, for you’ve done the same for me. I guess Mary Nestor knows you by this time, or, if she doesn’t, she never will. But what’s the big idea?”

“Oh, I’ve just got a notion in my head,” said Tom. “I want to go to the office a moment to jot down some memoranda before I forget them. ’Phone Mary I’ll be over as soon as I can. See you later.”

“Cheek!” exclaimed Ned, and with his merry whistle he hurried off in the darkness. “I only hope Mary speaks to you when you finally get to see her,” floated back to Tom.

“Don’t you worry about Mary,” advised the young inventor. “I’ll explain to her. And tell her I’ll be along in about half an hour. I really forgot all about the engagement.”

“I’ll say you did!” playfully mocked Ned.

Then, with his chum out of the way, Tom gave himself to trying to solve the mystery. For mystery he believed it to be. Seeing a man step behind a bush and, on arriving at the bush, to find nothing of the man there was surprising, to say the least.

Sensing that it would soon be so dark that it would be useless to investigate without an illuminant of some sort, Tom made haste to gain what advantage he could from the fast-fading light. He looked sharply about without moving from his place behind the bush on the other side of which he had seen the man disappear. Then, as he could pick up here no clew to the strange happening, the young inventor moved around to the other side.

The light was a little better here and Tom saw something that made him fairly gasp with astonishment. He had moved somewhat away from the bush and almost at his feet was an opening in the ground.

“This explains it!” murmured Tom, half aloud. “A hole in the ground! He went down there. I knew he couldn’t have dug himself in as quickly as that. But that hole! I never saw it before. It isn’t any of our doing. I’d have known about it if it were.”

All the land there belonged to Tom and his father. It was a big field surrounding the fenced-in plant, and often the smooth part of the field was used as a landing place for aeroplanes.

Cautiously approaching the opening in the ground and wondering more and more how it had gotten there without his knowledge, Tom saw that it had been closed by some planks placed over it. These were now tossed to one side, as if they had been hurriedly displaced. Scattered about was loose earth which had evidently covered the planks, thus hiding them from the view of a casual observer.

“A secret opening!” murmured Tom. “This is certainly the queerest thing I’ve ever seen! What does it mean?”

His surprise increased when, as he drew near to the edge of the opening, he saw a rough flight of plank steps going down into the hole. The young man caught his breath sharply, it was so astounding. But with Tom Swift to see and think was to act, and a moment later he began a descent of the steps into the mysterious hole. It might have been the part of discretion to wait until daylight, but a secret opening like this, so near the Swift plant, could mean but one thing, Tom reasoned.

“Some one is trying to put up a game on us,” he decided. “Unknown to us he has made a tunnel under our plant. There’s something funny here! I’m going to see what it is.”

Tom had fairly to feel his way down the flight of plank steps. They were rough and uneven, but solidly built. The young inventor counted them as he descended so he would know how to come back. Now that his head was below the level of the ground it was so dark that it was as if a velvet robe had been wrapped about him.

He counted ten steps down, and was cautiously feeling about with his right foot extended to ascertain if there were any more, when suddenly he felt the presence of some one near him. He caught the sound of breath fiercely drawn in, as if his unknown and unseen companion, there in the darkness, was nerving himself for an attack.

Instinctively Tom drew back, his hands pressed to the planked sides of the opening down which he had descended. He could feel, rather than see, some one leaning toward him. A sweet, sickening odor came to his nostrils. He felt a hand pressed over his face—a hand that held a damp rag which gave off that overpowering perfume.

“Here! What’s this? Who—who——” But Tom Swift’s voice became a mere gurgle in his throat. His legs became limp. His head whirled and he seemed lifted up and carried through measureless miles of space on the wings of some great bird.

Then Tom’s senses left him. He knew no more.

CHAPTER II
WAITING IN THE DARK

Just how long Tom Swift remained unconscious he himself did not know. It may have been several hours, for when he came to himself he felt a curious stiffness about his muscles as if he had lain for some time on the damp ground.

And he was on the ground—a fact he ascertained by feeling about with his hands, his fingers encountering damp, packed earth and the smooth surface of stones set in the soil.

“Where in the world am I, and what happened?” thought Tom, as soon as he could collect his senses enough to do any thinking. “Gee, but I sure do feel queer!”

There was a sickish taste in his mouth—a sense of sweetness, such as he remembered followed a slight operation he had undergone some years before when an anæsthetic had been given him.

“They doped me all right—that’s what they did,” mused Tom. “Ether, chloroform, or something like that. It knocked me out. But I’m beginning to feel all right again—no headache or anything like that. But what does it all mean, and where am I?”

Those were questions not easily answered.

While Tom Swift is trying to collect his senses and to remember, in their sequence, the events which led up to his queer predicament, may I take just a moment of your time, if you are a new reader, to tell you who Tom was?

The first book of this series, “Tom Swift and His Motor Cycle,” introduces you to the young inventor. His father, Barton Swift, was a widower, living in the old homestead at Shopton on Lake Carlopa. The Swift home was on the outskirts of the town and in a building not far from the house Barton Swift began work on a series of inventions which were destined to make him and his son famous. Tom’s mother was dead, but Mrs. Baggert, the housekeeper, looked well after the material welfare of Tom and his father.

In due time Tom began to follow in his father’s footsteps, working at small inventions until, when a sturdy youth, he became possessed of a motorcycle. He bought the machine of an eccentric individual named Wakefield Damon, who lived in the neighboring town of Waterfield. Mr. Damon set out to learn to ride his new machine.

“But bless my porous plaster!” the queer man would exclaim in telling the story, “I never thought the contraption was going to climb trees!”

Which it did, or tried to, because Mr. Damon did not know how to manage it. The result was that the rider was injured and the motorcycle badly smashed and Tom, near whose home the accident occurred, became the owner of the machine.

How he repaired it, added some improvements, and what he did with the machine are fully set forth in the book. It was the beginning of a long friendship with Mr. Damon, and also the real start of Tom’s inventive career.

Those of you who have followed him in his successes, from his motor boat to “Tom Swift’s Chest of Secrets,”—the volume immediately preceding this one—need not be told of Tom’s activities. He had made some wonderful pieces of apparatus and had had some startling adventures. In some of these his father and Mr. Damon had shared. So, also, had Ned Newton, Tom’s closest friend and now the treasurer of the Swift Construction Company.

Mary Nestor, of whom Ned had spoken, was a beautiful girl whom Tom hoped to marry some day, and Ned Newton was interested in a similar manner in Mary’s friend, Helen Morton.

As Tom sat there in the darkness, trying to puzzle out where he was and how he had gotten there, his thought flashed to Mary.

“I wonder what she’ll think?” he mused. “I’d better get to a telephone and explain. Let’s see. I was coming back from town and I saw some fellow sneaking along behind the bushes. I met Ned. I went down a flight of stairs in a hole—though how they could be there and I not know it, is more than I can fathom. Then they doped me. But who did it and why, I don’t know. I’ll soon find out, though. Wonder how long I’ve been here? Feels like a week, I’m so stiff. But I’m not hurt, thank goodness!”

Tom stretched out his arms in the darkness. They responded to the action of his muscles. But when he tried to get up and walk—well, he simply could not!

“Chained fast!” cried Tom, aloud. His hands had sought his left ankle when he found that something held him fast there, and his fingers had come in contact with a chain.

For a moment he felt a sinking sensation. To be chained fast in the dark, at the bottom of some cave or dungeon, located he knew not where, was enough to take the heart out of any one. But not for long did Tom Swift give way to despair.

He gave a vigorous tug to the chain about his ankle. After all, it might only be lying across it or loosely twisted. But it needed only one effort on his part to loosen the links to let him know that he was bound fast. Whoever had put the chain on his ankle had done so with serious intentions of holding the young inventor captive.

“Well, this is worse and more of it!” he mused grimly. “What does it all mean? It can’t be a plot to kidnap me. No one knew I was coming across the lots, for I didn’t know it myself until the last minute. And seeing that man sneaking along, discovering the secret stairs—it was all a series of accidents. Though it’s likely to prove a serious accident for me if I can’t get loose.”

Tom was nothing if not practical, and first he felt about with his hands to determine the exact nature of what it was that held him fast. He discovered, by the sense of touch, that something in the nature of a handcuff was snapped about his ankle. To this cuff, or leg-iron, was attached a chain. By following this, link by link, Tom found that the chain was made fast to a ring of iron which, in turn, was sunk into the stone side wall of the cave or tunnel in which he now found himself.

How far he was removed from the bottom of the flight of secret steps where he had been made unconscious, he did not know, any more than he knew where he was.

Having discovered what it was that held him fast and the nature of the chain and its fastenings, Tom, who had risen to his feet, stood silent a moment, listening. It was very black and very still in the cave, if such it was, and from the earthy, damp smell he concluded that he must be underground, or at least in some vault or cellar.

By test Tom found that he could move about five feet, such being the length of the chain. The leg-iron had been snapped or riveted about his ankle outside of his trousers. It was not tight enough to cause any pain, but it was snug enough to be impossible of removal.

“They’ve got me as tight as an animal in a trap!” grimly exclaimed the youth, when, by a series of tugs, he ascertained how securely the end of the chain was fast in the rocky wall. “Just like a trap, or a prisoner in an old-time dungeon!” bitterly reflected the young man. “All it needs to make a moving picture film is some beautiful maiden to come to my rescue with a file——”

Tom’s spoken words (for he was talking aloud to himself) came to a sudden end as he clapped a hand to the pocket of his coat.

“I’ve got ’em!” he fairly shouted, and he drew out a small paper parcel in which were two keen files. They were part of the purchases made just before stumbling on the mysterious man and finding the steps in the queer opening.

“Files—the hardest and best made!” he told himself. “They’ll cut through anything but a diamond. Luck’s with me, after all. They didn’t know I had these! Oh, boy!”

Everything seemed changed now! Though he was held fast, though he was in some secret dungeon, hope sang a song of joy in his heart.

For a moment Tom debated with himself as to the best end of the chain at which to begin filing. It would be more comfortable with that leg-iron off his ankle, but by feeling it in the darkness he could tell that it was broad and thick. It would take some time for even the keen, hard file to cut through it.

“I’ll file through one of the links close to the leg-iron,” decided Tom. “That won’t leave much to carry around, and it won’t take long to cut through a link—that is, unless they’re made of case-hardened steel.”

But the chain was of the ordinary sort, made of soft iron, and it did not take the young inventor long, practiced as he was in the use of tools, to file apart one of the links. True it was not easy in the darkness, and, more than once, the file slipped and cut Tom’s hands or fingers, for he changed from left to right and back to left in using the file, having taught himself to be ambidextrous in many operations.

At last he could feel that the link was nearly severed and then, inserting the small ends of the two files in it, he pried them apart. This leverage broke the thin remaining bit of iron and Tom was free.

That is, he was free to move about as he pleased, but he was still within the dark cave, and where it was he could not imagine.

“I’ve got to feel my way about,” he told himself. “It’s as dark as the inside of a pocket.”

So dark was it that Tom had to tread cautiously and with outstretched hands lest he bump into some obstruction. Whether he was moving toward the steps down which he had come or in the opposite direction, Tom had no means of knowing. His sense of touch alone guided him.

He could feel that he was walking along a tunnel, but the size of it he could only guess at. Then, suddenly, on making an elbow turn, he saw, glimmering in the distance, a faint light. It was the light of day, Tom knew, and by that he realized that he had been held captive all night.

“That makes it bad,” he mused. “Dad will have done a lot of worrying about me, I’m afraid. But I guess I’ll soon be out of here.”

Then, to his ears, came the murmur of voices—voices strange to him. So faint was the light in the distance that it was of no service to him where he stood waiting in the darkness; waiting for he knew not what.

The voices increased in loudness, showing that the speakers were approaching. Then he heard footsteps echoing strangely in the hollow tunnel.

“If there’s going to be a fight I’d better get ready for it,” Tom told himself fiercely. He stooped and began feeling about on the ground for a loose rock or a club. But he could find nothing. Then like a flash it came to him.

“One of the files! They’re pretty sharp on the handle end. As good as a knife! I’ll use it like a knife if I have to,” he mused desperately.

He drew one of the files from his pocket, grasped it firmly, and waited in the darkness for what was to happen next.

CHAPTER III
MASKED MEN

After the treatment that had been accorded him, Tom Swift rather welcomed than otherwise a chance to come to grips with the men who were responsible for his position. Usually even-tempered and generous, just now he felt eager for vengeance and he would not have cared much if two men had attacked him at once.

Strangely enough he did not feel weak or ill now. He had, somewhat, when he first regained his senses after having been overpowered by some drug. But his brain had cleared and he kept himself in such good physical trim all the while that even a night of unconsciousness had not sapped his strength.

The light in the distance did not increase any, from which Tom gathered that it was full daylight with the sun well above the horizon, and after that first murmur of voices and the sound of footsteps these sounds did not come any nearer. Nor did Tom catch a glimpse of any figures between himself and that little circle of light.

Then from some point outside the cave or tunnel he heard voices calling. They were louder than the first, and there seemed to be some dispute or disturbance.

The voices rose to a high pitch and then died away. Silence followed, and then came the sound of retreating footsteps.

“They’re going away!” exulted Tom. “Now I’ve got a chance to walk toward that daylight and see where I am. Maybe I’d better wait a few minutes, though. They may come back.”

He waited what he thought was several minutes and then, hearing no other sounds of voices or footsteps, began a cautious approach toward that gleam of light. What a blessed thing light was, after all that black and clinging darkness!

In silence Tom crept on, advancing one foot after the other cautiously, and keeping one hand extended to give warning of his approach toward any obstruction while in his other hand he held the file like a dagger, ready to use.

But there was no occasion for this. A little later he found himself standing in a circle of daylight illumination that filtered down an inclined shaft which led out of a tunnel, such as Tom could now ascertain he was in. A natural tunnel it appeared to be, with rocks jutting out here and there in the earthen sides. Roughly the tunnel was in the form of a half circle, the floor being flat and the roof arched. The inclined entrance led upward in a gentle slope.

“Well, now to see what’s up there!” said Tom to himself, taking a long breath and holding his weapon ready. He tensed his muscles and steeled his nerves for what he felt might be a desperate struggle. Yet he did not shrink back.

As he advanced cautiously, step by step, up the incline that led to daylight and the outer world, he felt at first a sense of disappointment when he saw no one with whom he might come to grips. He had been treated so meanly that it would have been a source of satisfaction to have had it out in a rough-and-tumble fight with those responsible.

But, to his surprise, Tom pushed his way out through a tangle of underbrush and bushes which grew about this end of the tunnel and found none to dispute him. This surprise was added to when he looked about him and found out where he was.

“On Barn Door Island!” exclaimed Tom. “Of all places! Barn Door Island! But how did I get here? It’s miles away from where I went down those steps near our plant. Of all places! Barn Door Island!”

This was a small island in Lake Carlopa which had been named Barn Door because, some time or other, one of the early settlers happened to remark that it was no larger than the door of a barn. The island was at the end of the lake farthest removed from Shopton and the Swift plant.

“I never knew there was an entrance to a tunnel here!” said Tom, as he looked about him. “But then I’ve never explored here very much.”

Nor had any of the other lads of Shopton. Barn Door Island was a barren place—merely a collection of scrubby trees and tangled bushes and great boulders set down at the swampy end of Lake Carlopa. It was not a good fishing location and too dreary for picnic parties, so Barn Door was seldom visited.

“But if I had an idea there was a tunnel entrance here—the beginning of a passage that led under the lake and under the land right up to our place I’d have done a lot of exploring, that’s sure!” Tom told himself. “That’s a natural tunnel, I’m positive of it, at least most of it is. Somebody went along it until they got to the end near our fence. Then they broke out, put in those steps and made the plank covering for the opening. They put earth over the planks so no one would see them. That part must have been done recently, for we were trying airships out in that field a month ago and I landed right near that bush behind which the man disappeared. I know I did, for I remember thinking I might crash into the fence. So the land end of this queer tunnel has only been opened lately. This island end must have been here a long while. But it’s queer no one knew of it. And I wonder what it’s being used for? Something to do with our business, I’m sure. Our enemies are at work again!”

Tom quickly reviewed the situation in his mind. Since his Chest of Secrets had been taken and he had had so much trouble in recovering it, he had been very cautious about his plans of new inventions. Suspecting several of his newer employes, he had gotten rid of them and had taken great precautions, on the advice of Ned and his father.

“But if there’s a tunnel from this lonely island under the lake and beneath the shore right up almost to our plant, it means that something desperate is in the wind,” reasoned Tom. “They must have resented my blundering into it as I did, and they tried to put me out of the way. After they doped me they must have carried me a long way through the tunnel, to chain me fast near this end.

“Well, I’m free now, and out in the open. About noon, I should judge by the sun and by the way my stomach feels,” Tom went on, with a grim smile, for he was getting hungry and feeling a bit weak now. “I hope it isn’t more than the next day,” he went on, meaning the day following his night encounter with Ned.

He looked about him. Barn Door Island was about five acres in extent, large enough, on account of its wild character, to give concealment to any number of enemies. But if there were any such here now they did not show themselves as Tom eagerly and anxiously scanned the somewhat wild landscape.

“Well, now that I know where I am, though I can’t understand how or why I was put in that tunnel and chained,” mused the lad, as he looked at the iron still on his leg, “I might as well try to get back home. It’s pretty lonesome down here, and I don’t know whether I can signal any one or not. But it isn’t far to the mainland and I can swim it. Though if I’m going to do that I’d better file this iron off. No fun swimming with that bracelet on my ankle.”

He looked about for a place where he could sit down and file in comfort at the remaining evidence of his recent bondage when, as he approached the shore, he saw, pulled up close to a rude dock in a little cove, a small motor boat.

“Well, if this isn’t luck!” cried Tom. “There must be some picnic party here and that’s their boat. But no—wait a minute! Maybe it belongs to those men I heard talking in the tunnel. I’ll wager that’s it. And this is my chance! I’ll appropriate their boat since they treated me like a roughneck. I’ll get back home, maybe in time to stop their trick—whatever it is.”

There was not much about a motor boat that Tom Swift did not know, and it took him but a few seconds to ascertain that this one was in good working order. No longer considering the need of filing off the leg-iron, Tom pushed the boat out from the dock, which was merely a few old logs and planks, and prepared to start the engine.

He turned the flywheel and, almost at the first revolution after he had thrown the spark switch, the engine was in motion. But even as it glided out of the little cove Tom was aware of the presence of another craft. Around one of the points of the cove, as he guided his boat out, the other swung in, and a glance showed it to be occupied by four rough-looking men.

Two of them wore masks. The faces of the other two were familiar to Tom, for they were two of his recently discharged workmen—Kenny and Schlump!

Tom had a feeling that some desperate work was in prospect. The attack on him, the rendering of him unconscious, his being chained fast—all this was more than accidental coincidence following his trailing of the man who had disappeared down in the tunnel.

For a moment those in the second boat remained gazing, spellbound, it seemed, at Tom, who was rapidly putting distance between himself and those he felt were his enemies. The boat he had so unexpectedly found proved to be a speedy little craft. But the other was also.

“There’s Tom Swift now!” cried Schlump, pointing.

“Where?” asked one of the masked men.

“In our boat!” Schlump answered. “Come back here!” he roared, shaking his fist at Tom.

“Come back nothing!” taunted the young inventor.

“Don’t stop to talk!” shouted one of the masked men. “Speed up! We must catch Swift at any cost!”

CHAPTER IV
A NIGHT OF WORRY

About nine o’clock on the night when Tom Swift had witnessed the strange actions of the man who so mysteriously disappeared, the telephone bell tinkled in the Swift home. As Tom’s father was reading a scientific book in which he was much engrossed, Mrs. Baggert went to the instrument. Half-interested in the conversation, Mr. Swift listened to the one-sided talk, hearing Mrs. Baggert say:

“Oh, how do you do, Miss Nestor? No, Tom isn’t here. I haven’t seen him since supper. His father is here. Do you want to speak to him? What’s that? Oh, all right. Yes, I’ll be sure to tell him.”

“Isn’t Tom over at Mary’s house?” asked the aged inventor, with a shade of anxiety in his voice as he looked up from his book. He had guessed at what he had not heard.

“No, he isn’t there, and Miss Nestor is getting tired of waiting, I guess,” answered the housekeeper.

“Where is Tom?” asked his father.

“I don’t know,” Mrs. Baggert replied. “He started for Shopton right after supper, saying he had to buy some things at the hardware store before it closed. I heard Mr. Ned tell him not to be late and Tom promised he wouldn’t. I didn’t know then what Mr. Ned warned him not to be late for, but I can guess now that it was in calling on Miss Nestor.”

“And he hasn’t arrived there yet,” murmured Mr. Swift. “That’s a bit odd, for Tom doesn’t usually break his engagements—especially with Mary Nestor,” and he smiled a little.

“Oh, Miss Nestor told me to say to you that she wasn’t in the least worried,” Mrs. Baggert made haste to add. “She says she knows Tom is very busy and something may have come up at the last moment. She says he promised to take her to see a moving picture this evening. She has been waiting some time, and she called up to say if he couldn’t come it would be all right, and she would go to the second show with her mother. That’s all the message was about.”

“Oh, well, I guess it’s all right then,” returned Mr. Swift, with an air of relief. “Tom is probably delayed in Shopton, getting what he wanted. But he should have telephoned, either here or to Mary. It isn’t fair to keep a young lady waiting like that.”

“Miss Nestor said to be sure and tell him she wasn’t at all put out because he didn’t come,” said Mrs. Baggert. “She knows it must be some good reason that kept him away.”

“I hope it is,” said Mr. Swift. “But it isn’t like Tom to stay away without sending some word.”

As the hours passed and the young inventor neither returned nor communicated, the anxiety in his father’s mind grew, until, about midnight when the front door was heard to open, Mr. Swift cried:

“Is that you, Tom? Where have you been? Why didn’t you send some word? And you have broken your promise to call on Mary!”

“This isn’t Tom,” came in the voice of Ned Newton, who, of late, had been living at the Swift home. “But you don’t mean to tell me Tom isn’t here! I was just going to tell him he was in for a bad half hour the next time he called on Mary.”

“No, Ned, Tom isn’t here,” said Mr. Swift, who had sat up past his usual retiring hour to meet his son when he should arrive. “And he isn’t over at Mary’s house, either.”

“I know he isn’t there,” Ned said. “Helen and I stopped in on our way back from the pictures to find out why we hadn’t seen those two at the show. We found Mary a bit disturbed because Tom had neither called nor telephoned. That’s why I was going to tell him he was in for a bad time when next he sees Mary.”

“But he isn’t here,” said Mr. Swift. “I can’t understand it. He went over to Shopton directly after supper, Mrs. Baggert says, and he hasn’t returned.”

“Oh, yes, he came back,” Ned replied quickly. “I saw him.”

“Where?” cried the aged inventor.

“Just outside the big fence—on the landing field, in fact. Tom was on his way here then. He found what he wanted in some Shopton store, he told me, and I said he’d better hurry if he was going to keep his date with Mary. I was a bit late myself, so I left him and hurried on and he started for the house.”

“Then something has happened to him, for he never got here!” exclaimed Mr. Swift. “Something has happened!” He was getting excited and Ned did not like that, for the aged man’s health was far from good.

“Oh, not necessarily,” said Ned, in easier tones than his own feelings justified. “Tom’s all right, you can be sure of that. He knows how to take care of himself. Besides, how could anything happen at his own doorstep, so to speak? He was near the big fence.”

“Well, I’m sure something has happened,” Mr. Swift declared.

But Ned shook his head and smiled.

“More than likely,” he said, “Tom went into his private office to leave what he had bought in Shopton. Once he was at his desk he saw something he had forgotten to do, or he was taken with a sudden idea, and he sat down to make some note about it before it slipped out of his mind.

“It isn’t the first time he has done that, nor the first time he has made dates with Mary and then forgotten all about them. Don’t worry, Mr. Swift, you’ll find Tom in his private office over at the works.”

“That is easily settled,” was the answer. “I’ll call him on the telephone.”

There was an instrument in the living room where this conversation took place. The Swift home and works were linked by intercommunicating telephones, and Mr. Swift was soon plugging in on the circuit that connected with Tom’s private office. While he was waiting Mrs. Baggert came quietly into the room behind Mr. Swift.

“Is Tom home?” she asked of Ned, forming the words with her lips but not speaking, since she did not want to disturb Mr. Swift. Ned shook his head in negation, and a puzzled look spread over the face of the housekeeper.

“They’re too easily worried,” mused Ned, half-smiling. “Tom is all right, I’m sure.”

But this certainty gradually disappeared when several seconds went by and there was no answer to the bell that must be ringing in Tom’s office at the works.

“Isn’t he there?” Ned could not help asking.

“He doesn’t seem to be,” Mr. Swift replied.

“Maybe he’s on his way home,” Ned was saying when Mr. Swift suddenly exclaimed:

“Some one is at the ’phone now! Oh, hello, Koku!” he called into the transmitter. “Yes, I am here. But where’s Tom? Is he there? What? He isn’t? Has he been there? No!”

The silence on Mr. Swift’s part, following his last word, told Ned and Mrs. Baggert, more than anything else, how worried he was. He appeared to be listening to what the giant at the other end of the wire was saying. Then he spoke again:

“We’ll be right over, Koku. Yes, I’m coming and so is Mr. Newton. Don’t bring Eradicate? Well, he might be of some help. There’s no use in you being jealous. Look around until we get there. Tom may be in some of the other buildings!”

Slowly Mr. Swift replaced the receiver on the hook and then, turning to Ned and the housekeeper, he said:

“Tom isn’t there and hasn’t been since he left early in the afternoon. Koku has just made his rounds and hasn’t seen him, but I told him to go over the place again and have the other watchmen go with him. We’ll go ourselves and help search. I’m sure something has happened to Tom!”

CHAPTER V
A CRASH

Adventures in plenty had befallen Tom Swift, and in many of them Ned Newton had had a share. But always the young inventor had come out “on top of the heap,” so perhaps Ned was justified in his feeling that everything would be all right. Still he could understand and appreciate Mr. Swift’s worry.

Mr. Swift began looking for his hat and neck scarf, this last on the suggestion of his housekeeper.

A little later Mr. Swift, Ned, and Eradicate, the aged colored servant who had been in the Swift family many years, were on their way to the big plant, almost a mile distant. Ned had brought around to the door one of the small cars Tom used to make trips between his home and the shop, and it did not take long to reach the main gate in the big fence surrounding the place.

So many and varied had been the attempts to rob Tom of the fruits of his and his father’s brains that drastic measures to guard the place had been put into effect. The big fence, impossible to scale without long ladders, was one protection. In addition there were burglar alarm wires along the fence, which wires would give warning of any attempt to get under it or over it. In addition there was a strip of metal, charged with a high-power current which could be turned on at will, and this would give unauthorized trespassers a severe shock. It would not kill, but would disable for a time.

In addition there were other forms of protection, and so well guarded were the different gates, by night and day, that not even Tom himself could get in without due formality. So it was when the party of searchers arrived, they were not at once let in. The guard at the gate must first be certain who he was admitting.

“Good lan’!” exclaimed Eradicate. “Dish is plum’ foolishness! Cain’t yo’ look an’ see dat ole Massa Swift hisse’f am heah?”

“They have to be cautious, Rad,” said Ned, as he got out of the machine to give the password which was used each night. He saw Koku, the giant, coming down the path inside the fence, and the big man at once recognized the visitors.

Between Eradicate and Koku there was rivalry and jealousy because each one wanted to serve Tom without having the other called on. And no sooner had the colored man caught sight of the giant, as the latter told the watchman to open the gate, than Eradicate burst out with:

“Hu! Dat’s jest laik de big ninny! Don’t know his own folks! It’s a wonder to me dat Massa Tom keep him, he’s so dumb!”

“Black man talk much—not do anything!” growled the giant. “Look out or um be squashed,” and he opened and closed his enormous hands as if he wanted to clutch the old servant in them.

“That will do now, you two!” warned Mr. Swift. “We came to find Tom. Are you sure he isn’t here, Koku?”

“Not too sure, master; Not sure much about Master Tom—he go—he come—no can tell—no can do.”

“That’s about right,” agreed Ned, with a laugh. “Tom certainly goes and comes without telling any one much about it. But I gathered, from what he said to me just outside the fence, that he would be right along. There didn’t seem to be anything special he had to do.”

“Just where was it you met him?” asked Mr. Swift. “Let us start the investigation from there, you and I, Ned. Meanwhile, I will have all the other shops called by telephone from the central here.”

He gave orders to this effect to one of the watchmen and then with Ned went to the place, outside the fence, where Tom had last talked with his chum. But it was dark, and Ned, naturally, could not point out the exact spot, even with the aid of a flashlight.

“I think it was here, near this rock and bush,” he said, throwing the gleam of his little electric torch about.

But the dry, hard ground gave no clews to this superficial examination, and, as a matter of fact, Ned was about twenty-five feet off in his calculations, as was demonstrated later. Otherwise he and Mr. Swift might have seen the hole in the ground and the flight of stairs, for it was not until some time later that night—near morning, as a matter of fact—that the plotters replaced the planks and spread earth over them, thus hiding the secret entrance.

“Well, there doesn’t seem to be anything here,” said Mr. Swift, with an uneasy sigh as they made a hasty examination of the place. “We had better go inside and look there.”

But the search in and about the many buildings of the great Swift plant was no more successful. Every office and shop telephone had been rung. Some were answered by guards or watchmen who happened to be in the vicinity at the time the bell rang. But one and all said they had not seen Tom.

Then there was a check-up of every gate and entrance in the big fence, and at no place had Tom been admitted. Granting that his protective plans worked, he could not have entered his own plant without a record having been made of it, and there was none.

“There’s only one answer to this, then,” said Ned, when the search had ended.

“What’s the answer?” asked Mr. Swift.

“Tom didn’t come in here after he left me. He must have gone somewhere else.”

Mr. Swift looked at his watch.

“Do you suppose he could be at Mary’s now?” he asked.

“What time is it?”

“Three.”

“No, he wouldn’t be there at this hour!” declared Ned.

“He might,” replied Mr. Swift hopefully. “When Tom’s mind is busy on his inventions he forgets all about time. It would be just like him to forget that it was three o’clock in the morning and go to call on Mary.”

Ned shook his head, but Mr. Swift went on:

“I’m going to call her presently. But there is just one more place I want to search. It’s in the vault where we keep the Chest of Secrets, as Tom calls it. There is a private entrance to that he could come in by and not register the alarm nor be seen by any of the guards. He can switch off that alarm from his room at the house. I’ll look there. He may have gone there to see if there isn’t some way out in the trouble we’re in over the airline express patents.”

“Trouble?” questioned Ned, as they walked toward the vault.

“Yes. Tom and I haven’t spoken of it even to you, Ned, for the thing really isn’t in such shape that it can be talked about. But Tom has an idea, it may be nothing more than a dream, that he can establish a line of travel to cross our continent from New York to San Francisco between dawn and darkness. In other words, a coast-to-coast service, from ocean to ocean, by daylight—say sixteen hours—with no change.”

“No change!” cried Ned. “What’s the idea—refueling the planes in the air? Of course that has been done. But from coast to coast in sixteen hours without change! It can’t be done!”

“Tom thinks so,” said Mr. Swift. “That’s what he’s working on now. He has had some new models made, but there is trouble over the patent rights. Some one is trying to get his idea away from him. It may be that Tom came to the secret vault after he left you to make sure everything was all right, and he may be there yet.”

But the vault was unoccupied, nor had it been disturbed. Mr. Swift gave a hasty glance at several complicated and odd-looking models of aircraft in the concrete room, looked over a pile of papers, and said:

“Well, they haven’t been disturbed since Tom and I were here last, which proves my son hasn’t been here. But where is he? I’m beginning to get worried, Ned. More worried than ever!”

“Oh, he’ll be all right,” was the answer, though in his own heart Ned Newton could not help feeling apprehensive. “It may be, as you say, that he made a very late call on Mary, and her folks have probably asked him to stay all night, as they have done before.”

“I think the matter justifies me in calling Mr. Nestor on the telephone,” said Mr. Swift, as they emerged from the vault where the Chest of Secrets was stored. “It’s rather early to ring up anybody, but I guess they will understand.”

It was about four o’clock now, and already, in the east, a light was appearing, the sun was heralding the dawn. The early birds were beginning to sing. It would soon be morning, though not yet time for the wheels to begin humming in the Swift plant.

Going back to the office, where Koku reported that a second check-up had failed to disclose the whereabouts of the young inventor, Mr. Swift called the Shopton central operator and gave her the number of the Nestor house.

There was some little delay, as was natural when a call is made at that hour of the morning, but at length Mr. Nestor’s voice was heard.

“Who? Tom? No, he isn’t here—hasn’t been here,” was the message the aged inventor received. “What’s the matter?”

There was some further talk, and Mr. Swift briefly outlined what had happened.

“Don’t alarm Mary yet,” Mr. Swift cautioned his friend. “But I fear something has happened to Tom. I wish you would come over.”

“I will!” Mr. Nestor promised. “I’ll be over as soon as I can dress.”

“Tell him I’ll call for him,” Ned said to Mr. Swift, and this message went over the wires.

It was fully light when they went down into the yard where the small auto had been left. And suddenly the silence of the dawn, made musical by the twitterings of the birds, was broken by an increasing roar and throbbing noise.

“Airship!” grunted Koku.

“Suah enough!” exclaimed Eradicate, pointing up. “Dere she am!”

The throbbing sound became louder, and a moment later they saw the plane, a large one, approaching from the west.

“It’s Mr. Damon’s machine!” cried Ned. “What in the world is he flying so early for? He isn’t sure enough of himself to take that big plane out alone—he only got it the other day. Great Scott! Look! He’s going to hit your mooring mast!”

At one end of the big landing field outside the fence Tom had recently erected a tall steel mast, to which he moored a small dirigible balloon with which he was conducting experiments. As all looked up they saw Mr. Damon in his new machine headed straight for this mast.

“He doesn’t know it’s there!” cried Ned. “He’s sure going to hit!”

A moment later there was an alarming crash, and the top of the mast was seen to break off while one edge of the aeroplane’s left wing crumpled.

CHAPTER VI
AGAIN A PRISONER

The threat which Tom Swift heard the men in the pursuing motor boat mutter—a threat to catch him at any cost—was not needed to cause him to speed up the craft he had appropriated in an endeavor to escape. The sinister character of the men who wore the masks he could easily guess at. As to the others, he had begun to suspect them soon after they obtained work in his plant. Though they were clever mechanics, Tom did not like Kenny and Schlump and so had directed their discharge.

“They either have it in for me on that account,” mused Tom, as he made an adjustment to the motor to get more speed, “or else there’s something deeper in the plot. I guess they must have chained me up after I blundered into their tunnel. I’d like to know what all this means, but now is not the time to stop and find out. I must get away and ask questions afterward.”

It was to be a desperate chase—Tom Swift realized that from the tense and eager manner of the men in the boat now plowing through the waters of Lake Carlopa. They were forcing their craft to her best speed in an endeavor to overtake him.

“It’s a wonder they don’t begin shooting,” mused Tom. “A crowd of men like that, with two of them masked, won’t stop at shooting. Maybe I’d better get down a bit.”

He had been standing up in the boat, the better to make adjustments to the motor, but now, as he thought of the possibility of being fired upon, he crouched down to give less of a target to the men.

This move of his seemed to be misinterpreted by the pursuers, for one of them cried:

“There he goes overboard! One of you take after him!” This was shouted by one of the masked men, whose identity Tom Swift could only guess at, though he judged all of them to be some of his enemies.

But the young inventor had no intention of jumping out of the boat to swim for safety. He knew he would soon be overtaken and captured. His only chance lay in beating the scoundrels in a race. Besides, he was in no physical condition to endure a long swim. He had been in a most uncomfortable, cramped position all night, and the exertion of filing off the chain and going through the tunnel to emerge on Barn Door Island had tired him. He had had no breakfast, and this lack was now beginning to make itself felt more than at first.

But as he crouched down in the boat, where only a small part of his body showed above the rail, he remembered that he had in his pocket some chocolate candy. He had bought it the night before on his trip to town.

“I’ll make a breakfast on that,” mused Tom.

So as he crouched there in the boat he reached into his pocket, got out the cake of chocolate, and began to nibble it. In a few minutes he felt decidedly better. That “gone” feeling had left his stomach, and he began to relish, rather than fear, the outcome of the impending struggle.

The pursuit had started at the end of the lake where there was no town or other settlement, but at the pace it would not be more than half an hour before he would sight his home town.

For a few moments after the wild chase began Tom could hear the men in the other boat shouting after him:

“Come back here! Stop that boat! It’s ours! Stop or we’ll shoot!”

“Go ahead and shoot!” taunted Tom, hardly believing, after this delay, that they would go to this extreme. And they did not. Evidently their plan was to capture him alive.

Tom was so anxious to know whether or not his craft was keeping a sufficient distance in front of the other boat that he did not pay much attention to the course he was steering. The result was that, after he had swung out around a small island he was almost run down by a tug boat hauling some coal barges from one side of Lake Carlopa to the other.

Tom just had time to give the wheel a quick turn, and he fairly grazed one of the coal barges. This brought angry shouts from the captain of the tug who demanded to know:

“What in the name of thunderation are you trying to do, anyhow? Get yourself sunk? You soft-soaping landlubber, look where you’re going!”

Tom did not reply. He had half a notion to swing about, run up alongside the tug and appeal for help. Then a wild desire came into his mind to beat these men alone and single-handed if he could. It would be sportier that way.

As for his pursuers, when they saw the tug and barges they appeared to hesitate a moment, as if ready to give up the chase. But when they saw Tom keep on, they did the same, still chasing him.

For perhaps ten minutes more the chase was kept up. Tom could make out, by hasty observations over his stern, that three of the men were in consultation while the fourth one steered.

There now loomed up in front of Tom another island—a larger one than Barn Door, and he recognized it as the last one in this end of the lake before he could swing into the wider part of the water through which there was a straight course to Shopton.

“Once I get past there,” said Tom to himself, “I’m safe. They won’t dare chase me after that.”

As he neared the island he noticed that his motor was behaving in a peculiar manner. Every now and then it would miss an explosion. Then it would cough and wheeze a bit, after which it would go on again.

“What’s the matter, old girl?” asked Tom, for to him machinery was almost something alive and he talked to it as he would to a human being. “Are you getting tired?” he asked.

He looked over the working parts. They seemed to be all right. But again came a miss—then several of them. And finally, with a last cough and wheeze, the motor stopped altogether.

“No more gas!” exclaimed Tom. Well he knew that last wheeze when there is nothing more for the carburetor to feed on. He had used up the last drop of gasoline.

“Guess I’m done for,” mused Tom. “They must have known there wasn’t enough gas in the tank to carry me far. That’s why they kept on.” He looked back. The pursuers were perhaps five hundred feet astern, and Tom’s boat was so close to the island that he knew, with the headway still on, he could reach the shore.

He turned the prow toward the little cove and as soon as he was near enough he leaped over the bow, landing on the rocky shore, and ran up into the fastness of the island, which was covered with scrubby trees and bushes.

He looked about for a good place where he might conceal himself. He was sensible enough to know that to try to fight four men was taking on odds that were too heavy. He saw a little recess in the rocks, and squeezed into it.

A moment later he heard the voices of the men as they steered their boat up against the one he had deserted. Then he heard them jumping out on the gravelly beach.

“We’ve got him now!” one remarked.

“He can’t get away,” added another.

“Not unless he swims for it—we’ve got both boats!” said a third.

“He won’t try swimming—we could easily overtake him in our boat,” declared the fourth scoundrel, and Tom sensed that this was true.

“Scatter now, and find him!” one of the men ordered, and the hiding youth could hear them crashing about in the bushes looking for him. It was a foregone conclusion that they would find him sooner or later. Tom had not had time to look for a good hiding place, being under the necessity of taking the first one that offered.

So it was no wonder that, a few minutes after he had landed on the island, he heard some one coming nearer and nearer. He tried to force himself farther into the crevice of the rocks, but it was no use. His movements dislodged some small stones which fell with a rattle.

“Here he is!” cried a voice.

The next moment Tom was looking into the leering face of Kenny, and then along came Schlump.

The latter held a revolver, and even without this weapon Tom would have been forced to submit, for the two masked men soon came to the aid of their companions. Tom felt that discretion was the better part of valor in this instance. Besides, he hoped, by submitting quietly now, to escape by strategy a little later.

But he thought he would try a little bluff and bluster first, so he addressed the men with righteous indignation.

“You fellows have nerve!” he exclaimed. “What do you mean by treating me this way? I’ll have you all arrested for this and sent up.”

“Yes. Like you did Barsky, I suppose,” sneered one of the masked men.

Tom started at the mention of that name. Barsky or Blodgett, for he used both names, had been concerned in the theft of Tom’s Chest of Secrets. Barsky had been arrested, together with Renwick Fawn, and had been sent to jail.

“But maybe they have escaped,” thought Tom. “Maybe these two men are Fawn and Barsky.” He closely observed the actions of the men, but neither of them threw out his elbow in a jerky manner, which had been a characteristic of Fawn, nor were any of Barsky’s peculiarities observable in the other masked individual.

“Cut out the talk,” advised Kenny to the man who had mentioned Barsky’s name.

“What do you want of me?” boldly demanded Tom.

“You’ll find out soon enough,” answered Schlump.

But his intention of keeping secret the reason for their bold acts was not shared by the masked man who had spoken of the imprisoned Barsky. For approaching Tom and shaking his fist in the lad’s face the scoundrel exclaimed:

“You’re trying to beat us out of our invention, but it can’t be done! We’ve got you now where we want you!”

“Your invention—what do you mean?” asked Tom, genuinely puzzled.

“The airline express car,” was the unexpected answer. “That’s our invention, and we’re going to get patents on it ahead of you! We don’t intend to let you cheat us out of it. You stole our ideas and models, but we’ll use your models if we have to and get the patents that way.”

“You must be crazy!” exploded Tom. “Your invention! You don’t know what you’re talking about! That car is my own and my father’s idea! As soon as I get away from here I’ll make you sweat for what you’ve done to me!”