Over a year has passed since I wrote those lines. When they were written the hole which Jim Carpenter had burned with his battery of infra-red lamps through the heaviside layer, that hollow sphere of invisible semi-plastic organic matter which encloses the world as a nutshell does a kernel, was gradually filling in as he had predicted it would: every one thought that in another ten years the world would be safely enclosed again in its protective layer as it had been since the dawn of time. There were some adventurous spirits who deplored this fact, as it would effectually bar interplanetary travel, for Hadley had proved with his life that no space flyer could force its way through the fifty miles of almost solid material which barred the road to space, but they were in the minority. Most of humanity felt that it would rather be protected against the denizens of space than to have a road open for them to travel to the moon if they felt inclined.

To be sure, during the five years that the hole had been open, nothing more dangerous to the peace and well-being of the world had appeared from space than a few hundreds of the purple amoeba which we had found so numerous on the outer side of the layer, when we had traveled in a Hadley space ship up through the hole into the outer realms of space, and one lone specimen of the green dragons which we had also encountered. The amoeba had been readily destroyed by the disintegrating rays of the guarding space-ships which were stationed inside the layer at the edge of the hole and the lone dragon had fallen a ready victim to the machine-gun bullets which had been poured into it. At first the press had damned Jim Carpenter for opening the road for these horrors, but once their harmlessness had been clearly established, the row had died down and the appearance of an amoeba did not merit over a squib on the inside pages of the daily papers.

While the hole in the heaviside layer was no longer news for the daily press, a bitter controversy still waged in the scientific journals as to the reason why no observer on earth, even when using the most powerful telescopes, could see the amoeba before they entered the hole, and then only when their telescopes were set up directly under the hole. When a telescope of even small power was mounted in the grounds back of Carpenter’s laboratory, the amoeba could be detected as soon as they entered the hole, or when they passed above it through space; but, aside from that point of vantage, they were entirely invisible.

Carpenter’s theory of the absorptive powers of the material of which the heaviside layer was composed was laughed to scorn by most scientists, who pointed out the fact that the sun, moon and stars could be readily seen through it. Carpenter replied that the rays of colored or visible light could only pass through the layer when superimposed upon a carrier wave of ultra-violet or invisible light. He stated dogmatically that the amoeba and the other denizens of space absorbed all the ultra-violet light which fell on them and reflected only the visible rays which could not pass through the heaviside layer because of the lack of a synchronized carrier wave of shorter wave-length.

Despetier replied at great length and showed by apparently unimpeachable mathematics that Carpenter was entirely wrong and that his statements showed an absolute lack of knowledge of the most elementary and fundamental laws of light transmission. Carpenter replied briefly that he could prove by mathematics that two was equal to one and he challenged Despetier or anyone else to satisfactorily explain the observed facts in any other way. While they vainly tried to do so, Carpenter lapsed into silence in his Los Angeles laboratory and delved ever deeper into the problems of science. Such was the situation when the attack came from space.

My first knowledge of the attack came when McQuarrie, the city editor of the San Francisco Clarion, sent for me. When I entered his office he tossed a Los Angeles dispatch on the desk before me and with a growl ordered me to read it. It told of the unexplained disappearance of an eleven year old boy the night before. It looked like a common kidnapping.

“Well?” I asked as I handed him back the dispatch.

With another growl he tossed down a second telegram. I read it with astonishment, for it told of a second disappearance which had happened about an hour after the first. The similarity of the two cases was at once apparent.

“Coincidence or connection?” I asked as I returned it.

“Find out!” he replied. “If I knew which it was I wouldn’t be wasting the paper’s money by sending you to Los Angeles. I don’t doubt that I am wasting it anyway, but as long as I am forced to keep you on as a reporter, I might as well try to make you earn the money the owner wastes on paying you a salary, even although I know it to be a hopeless task. Go on down there and see what you can find out, if anything.”

I jotted down in my notebook the names and addresses of the missing children and turned to leave. A boy entered and handed McQuarrie a yellow slip. He glanced at it and called me back.

“Wait a minute, Bond,” he said as he handed me the dispatch. “I doubt but you’d better fly down to Los Angeles. Another case has just been reported.”

I hastily copied down the dispatch he handed me, which was almost a duplicate of the first two with the exception of the time and the name. Three unexplained disappearances in one day was enough to warrant speed; I drew some expense money and was on my way south in a chartered plane within an hour.

On my arrival I went to the Associated Press office and found a message waiting for me, directing me to call McQuarrie on the telephone at once.

“Hello, Bond,” came his voice over the wire, “have you just arrived? Well, forget all about that disappearance case. Prince is on his way to Los Angeles to cover it. You hadn’t been gone an hour before a wire came in from Jim Carpenter. He says, ‘Send Bond to me at once by fastest conveyance. Chance for a scoop on the biggest story of the century.’ I don’t know what it’s about, but Jim Carpenter is always front page news. Get in touch with him at once and stay with him until you have the story. Don’t risk trying to telegraph it when you get it--telephone. Get moving!”

I lost no time in getting Carpenter on the wire.

“Hello, First Mortgage,” he greeted me. “You made good time getting down here. Where are you?”

“At the A. P. Office.”

“Grab a taxi and come out to the laboratory. Bring your grip with you: you may have to stay over night.”

“I’ll be right out, Jim. What’s the story?”

His voice suddenly grew grave.

“It’s the biggest thing you ever handled,” he replied. “The fate of the whole world may hang on it. I don’t want to talk over the phone; come on out and I’ll give you the whole thing.”

An hour later I shook hands with Tim, the guard at the gate of the Carpenter laboratory, and passed through the grounds to enter Jim’s private office. He greeted me warmly and for a few minutes we chatted of old times when I worked with him as an assistant in his atomic disintegration laboratory and of the stirring events we had passed through together when we had ventured outside the heaviside layer in his space ship.

“Those were stirring times,” he said, “but I have an idea, First Mortgage, that they were merely a Sunday school picnic compared to what we are about to tackle.”

“I guessed that you had something pretty big up your sleeve from your message.” I replied. “What’s up now? Are we going to make a trip to the moon and interview the inhabitants?”

“We may interview them without going that far,” he said. “Have you seen a morning paper?”

“No.”

“Look at this.”

He handed me a copy of the Gazette. Streamer headlines told of the three disappearances which I had come to Los Angeles to cover, but they had grown to five during the time I had been flying down. I looked at Jim in surprise.

“We got word of that in San Francisco,” I told him, “and I came down here to cover the story. When I got here, McQuarrie telephoned me your message and told me to come and see you instead. Has your message anything to do with this?”

“It has everything to do with it, First Mortgage; in fact, it is it. Have you any preconceived ideas on the disappearance epidemic?”

“None at all.”

“All the better--you’ll be able to approach the matter with an unbiased viewpoint. Don’t read that hooey put out by an inspired reporter who blames the laxness of the city government; I’ll give you the facts without embellishment. Nothing beyond the bare fact of the disappearance is known about the first case. Robert Prosser, aged eleven, was sent to the grocery store by his mother about six-thirty last night and failed to return. That’s all we know about it, except that it happened in Eagle Rock. The second case we have a little more data on. William Hill, aged twelve, was playing in Glendale last night with some companions. They were playing ‘hide and go seek’ and William hid. He could not be found by the boy who was searching and has not been found since. His companions became frightened and reported it about eight o’clock. They saw nothing, but mark this! Four of them agree that they heard a sound in the air like a motor humming.”

“That proves nothing.”

“Taken alone it does not, but in view of the third case, it is quite significant. The third case happened about nine-thirty last night. This time the victim was a girl, aged ten. She was returning home from a moving picture with some companions and she disappeared. This time the other children saw her go. They say she was suddenly taken straight up into the air and then disappeared from sight. They, also claim to have heard a sound like a big electric fan in the air at the time, although they could see nothing.”

“Had they heard the details of the second disappearance?”

“They had not. I can see what you are thinking; that they were unconsciously influenced by the account given of the other case.”

“Consciously or unconsciously.”

“I doubt it, for the fourth case was almost a duplicate of the third. The fourth and fifth cases happened this morning. In the fourth case the child, for it was a nine year old girl this time, was lifted into the air in broad daylight and disappeared. This disappearance was witnessed, not only by children, but also by two adults, and their testimony agrees completely with that of the children. The fifth case is similar to the first: a ten year old boy disappeared without trace. The whole city is in a reign of terror.”

The telephone at Carpenter’s elbow rang and he answered it. A short conversation took place and he turned to me with a grim face as he hung up the receiver.

“Another case has just been reported to police headquarters from Beverly Hills,” he said. “Again the child was seen to be lifted into the air by some invisible means and disappeared. The sound of a motor was plainly heard by five witnesses, who all agree that it was just, above their heads, but that nothing could be seen.”

“Was it in broad daylight?”

“Less than an hour ago.”

“But, Jim, that’s impossible!”

“Why is it impossible?”

“It would imply the invisibility of a tangible substance; of a solid.”

“What of it?”

“Why, there isn’t any such substance. Nothing of the sort exists.”

Carpenter pointed to one of the windows of his laboratory.

“Does that window frame contain glass or not?” he asked.

I strained my eyes. Certainly nothing was visible.

“Yes,” I said at a venture.

He rose and thrust his hand through the space where the glass should have been.

“Has this frame glass in it?” he asked, pointing to another.

“No.”

He struck the glass with his knuckle.

“I’ll give up,” I replied. “I am used to thinking of glass as being transparent but not invisible; yet I can see that under certain light conditions it may be invisible. Granted that such is the case, do you believe that living organisms can be invisible?”

“Under the right conditions, yes. Has any observer been able to see any of the purple amoeba which we know are so numerous on the outer side of the heaviside layer?”

“Not until they have entered the hole through the layer.”

“And yet those amoeba are both solid and opaque, as you know. Why is it not possible that men, or intelligences of some sort, are in the air about us and yet are invisible to our eyes!”

“If they are, why haven’t we received evidence of it years ago?”

“Because there has only been a hole through the heaviside layer for six years. Before that time they could not penetrate it any more than poor Hadley could with his space ship. They have not entered the hole earlier because it is a very small one, at present only some two hundred and fifty yards in diameter in a sphere of over eight thousand miles diameter. The invaders have just found the entrance.”

“The invaders? Do you think that the world has been invaded?”

“I do. How else can you explain the very fact which you have just quoted, that no evidence of the presence on these invisible entities has previously been recorded?”

“Where did they come from?”

“They may have come from anywhere in the solar system, or even from outside it but I fancy, that they are from Mars or Venus.”

“Why so?”

“Because they are the two planets nearest to the earth and are the ones where conditions are the most like they are on the earth. Venus, for example, has an atmosphere and a gravity about .83 of earthly gravity, and life of a sort similar to that of the earth might well live there. Further, it seems more probable that the invaders have come from one of the nearby planets than from the realms of space beyond the solar system.”

“What about the moon?”

“We can dismiss that because of the lack of an atmosphere.”

“It sounds logical, Jim, but the idea of living organisms of sufficient size to lift a child into the air who are invisible seems a little absurd.”

“I never said they were invisible. I don’t think they are.”

“But they must be, else why weren’t they seen?”

“Use your head, First Mortgage. Those purple amoeba we encountered were quite visible to us, yet they are invisible to observers on the earth.”

“Yes, but that is because the heaviside layer is between them and the earth. As soon as they come below it they can be seen.”

“Exactly. Why is it not possible that the Venetians, or Martians, or whoever our invaders are, have encased themselves and their space flyer in a layer of some substance similar to the heaviside layer, a substance which is permeable to light rays only when a large proportion of ultra-violet rays accompany the visible rays? If they did this and then constructed the walls of their ship of some substance which absorbed all the ultra-violet rays which fell on it; not only would the ship itself be invisible, but also everything contained in it--and yet they could see the outside world easily. That such is the case is proved by the disappearance of those children in mid-air. They were taken into a space ship behind an ultra-violet absorbing wall and so became invisible.”

“If the walls absorbed all the ultra-violet and were impermeable to light without ultra-violet, the ship would appear as a black opaque substance and could be seen.”

“That would be true except for one thing which you are forgetting. The heaviside layer, as I have repeatedly proved, is a splendid conductor of ultra-violet. The rays falling on it are probably bent along the line of the covering layer so that they open up and bend around the ship in the same manner as flowing water will open up and flow around a stone and then come together again. The light must flow around the solid ship and then join again in such a manner that the eye can detect no interruption.”

“Jim, all that sounds reasonable, but have you any proof of it?”

“No, First Mortgage, I haven’t--yet; but if the Lord is good to us we’ll have definite proof this afternoon and be in a position to successfully combat this new menace to the world.”

“Do you expect me to go on another one of your crack-brained expeditions into the unknown with you?”

“Certainly I do, but this time we won’t go out of the known. I have our old space flyer which we took beyond the heaviside layer six years ago ready for action and we’re going to look for the invaders this afternoon.”

“How will we see them if they are invisible?”

“They are invisible to ordinary light but not to ultra-violet light. While most of the ultra-violet is deflected and flows around the ship or else is absorbed, I have an idea that, if we bathe it in a sufficient concentration of ultra-violet, some would be reflected. We are going to look for the reflected portion.”

“Ultra-violet light is invisible.”

“It is to the eye, but it can be detected. You know that radium is activated and glows under ultra-violet?”

“Yes.”

“Mounted on our flyer are six ultra-violet searchlights. By the side of each one is a wide angle telescopic concentrator which will focus any reflected ultra-violet onto a radium coated screen and thus make it visible to us. In effect the apparatus is a camera obscura with all lens made of rock crystal or fused quartz, both of which allow free passage to ultra-violet.”

“What will we do if we find them?”

“Mounted beneath the telescope is a one-pounder gun with radite shells. If we locate them, we will use our best efforts to shoot them down.”

“Suppose they are armed too?”

“In that case I hope that you shoot faster and straighter than they do. If you don’t--well, old man, it’ll just be too damned bad.”

“I don’t know that the Clarion hires me to go out and shoot at invisible invaders from another planet, but if I don’t go with you, I expect you’d just about call up the Echo or the Gazette and ask them for a gunner.”

“Just about.”

“In that case, I may as well be sacrificed as anyone else. When do we start?”

“You old faker!” cried Jim, pounding me on the back. “You wouldn’t miss the trip for anything. If you’re ready we’ll start right now. Everything is ready.”

“Including the sacrifice,” I replied, rising. “All right, Jim, let’s go and get it over with. If we live, I’ll have to get back in time to telephone the story to McQuarrie for the first edition.”

I followed Jim out of the laboratory and to a large open space behind the main building where the infra-red generators with which he had pierced the hole through the heaviside layer had been located. The reflectors were still in place, but the bank of generators had been removed. A gang of men were hard at work erecting a huge parabolic reflector in the center of the circle, about the periphery of which the infra-red reflectors were placed. In an open space near the center stood a Hadley space ship, toward which Jim led the way.

I wondered at the activity and meant to ask what it portended, but in the excitement of boarding the flyer forgot it. I followed Jim in; he closed the door and started the air conditioner.

“Here, First Mortgage,” he said as he turned from the control board and faced me, “here are the fluoroscopic screens. They are arranged in a bank, so that you can keep an eye on all of them readily. Beneath each telescope is an automatic one-pounder gun with its mount geared to the telescope and the light, so that the gun bears continually on the point in space represented by the center of the fluoroscopic screen which belongs to that light. If we locate anything, turn your beam until the object is in the exact center of the screen where these two cross-hairs are. When you have it lined up, push this button and the gun will fire.”

“What about reloading?”

“The guns are self-loading. Each one has twenty shells in its magazine and will fire one shot each time the button is pushed until it is empty. If you empty one magazine, I can turn the ship so that another gun will bear. This gives you a total of one hundred and twenty shots quickly available; there are sixty extra rounds, which we can break out and load into the magazines in a few seconds. Do you understand everything?”

“I guess so. Everything seems clear enough.”

“All right; sit down and we’ll start.”

I took my seat, and Jim pulled the starting lever. I was glued to the seat and the heavy springs in the cushion were compressed almost to their limit by the sudden acceleration. As soon as we were well clear of the ground Jim reduced his power, and in a few moments we were floating motionless in the air, a thousand feet up. He left the control board and came to my side.

“Start your ultra lights,” he said as he joined me. “We may be able to spot something from here.”

I started the lights and we stared at the screens before us. Nothing appeared on any of them except the one pointing directly down, and only an image of the ground, appeared on it. Under Jim’s tutelage I swung the beams in wide circles, covering the space around us, but nothing appeared.

“Those beams won’t project over five miles in this atmosphere,” he said, “and the ship we are looking for may be so small that we would have trouble locating it at any great distance. I am going to move over near the scene of the last disappearance. Keep your lights swinging and sing out if you see anything on the screens.”

I could feel the ship start to move slowly under the force of a side discharge from the rocket motor, and I swung the beams of the six lights around, trying to cover the entire area about us. Nothing appeared on the screens for an hour, and my head began to ache from the strain of unremitting close observation of the glowing screens. A buzz sounding over the hum of the rocket motor attracted my attention; Jim pulled his levers to neutral with the exception of the one which maintained our elevation and stepped to an instrument on the wall of the flyer.

“Hello,” he called. “What? Where did it happen? All right, thanks, we’ll move over that way at once.”

He turned from the radio telephone and spoke.

“Another disappearance has just been reported,” he said. “It happened on the outskirts of Pasadena. Keep your eyes open: I’m going to head in that direction.”

A few minutes later we were floating over Pasadena. Jim stopped the flyer and joined me at the screens. We swung our beams in wide circles to cover the entire area around us, but no image on the screens rewarded us.

“Doggone it, they must have left here in a hurry,” grumbled Jim.

Even as he spoke the flyer gave a lurch which nearly threw me off my seat and which sent Jim sprawling on the floor. With a white face he leaped to the control board and pulled the lever controlling our one working stern motor to full power. For a moment the ship moved upward and then came to a dead stop, although the motor still roared at full speed.

“Can’t you see anything, Pete?” cried Jim as he threw our second stern motor into gear.

Again the ship moved upward for a few feet and then stopped. I swung the searchlights frantically in all directions, but five of the screens remained blank and the sixth showed only the ground below us.

“Not a thing,” I replied.

“Something ought to show,” he muttered, and suddenly shut off both motors. The flyer gave a sickening lurch toward the ground, but we fell only a hundred yards before our motion stopped. We hung suspended in the air with no motors working. Jim joined me at the screens and we swung the lights rapidly without success.

“Look, Pete!” Jim cried hoarsely.

My gaze followed his pointing finger and I saw the door of our flyer springing out as though some force from the outside were trying to wrench it open. The pull ceased for an instant, then came again; the sturdy latches burst and the door was torn from its hinges. Jim swung one of the searchlights until the beam was at right angles to the hull of the flyer and pressed the gun button. A crash filled the confined space of the flyer as a one-pounder radite shell tore out into space.

“They’re there but still invisible,” he exclaimed as he shifted the direction of the gun and fired again. “I am shooting by guess-work, but I might score a hit.”

He changed the direction of the gun again, but before he could press the button he was lifted into the air and drawn rapidly toward the open door.

“Shoot, Pete!” he shouted. “Shoot and keep on shooting--it’s your only chance!”

I turned to the knobs controlling the guns and lights, but, before I could make a move, something hard and cold grasped me about the middle and I was lifted into the air and drawn toward the open door after Jim. I tore at the thing holding me with my hands, but it was a smooth round thing like a two-inch thick wire, and I could get no grip on it to loosen it. Out through the door I went and was drawn through the air a few feet behind Jim. He moved ahead of me for fifteen or twenty feet and then vanished in mid-air. I dared not struggle in mid-air and I was drawn through a door into a large space flyer which became visible as I entered it. The flexible wire or rod which had held me uncoiled and I was free on the floor beside Jim Carpenter. This much was clear and understandable, but when I looked at the crew of that space ship, I was sure that I had lost my mind or was seeing visions. I had naturally expected men, or at least something in semi-human form, but instead of anything of the sort, before me stood a dozen gigantic beetles!

I rubbed my eyes and looked again. There was no mistaking the fact that we had been captured by a race of gigantic beetles flying an invisible space ship. When I had time later to examine them critically, I could see marked differences between our captors and the beetles we were accustomed to see on the earth besides the mere matter of size. To begin with, their bodies were relatively much smaller, the length of shell of the largest specimen not being over four feet, while the head of the same insect, exclusive of the horns or pinchers, was a good eighteen inches in length. The pinchers, which by all beetle proportions should have been a couple of feet long at the least, did not extend over the head a distance greater than eight inches, although they were sturdy and powerful.

Instead of traveling with their shells horizontal as do earthly beetles, these insects stood erect on their two lower pairs of legs, which were of different lengths so that all four feet touched the ground when the shell was vertical. The two upper pairs of legs were used as arms, the topmost pair[A] being quite short and splitting out at the end into four flexible claws about five inches long, which they used as fingers. These upper arms, which sprouted from a point near the top of the head, were peculiar in that they apparently had no joints like the other three pairs but were flexible like an elephant’s trunk. The second pair of arms were armed with long, vicious-looking hooks. The backplates concealed only very rudimentary wings, not large enough to enable the insects to fly, although Jim told me later that they could fly on their own planet, where the lessened gravity made such extensive wing supports as would be needed on earth unnecessary.

[Footnote A: Mr. Bond has made a laughable error in his description. Like all of the coleoptera, the Mercurians were hexapoda (six legged). What Mr. Bond continually refers to in his narrative as “upper arms” were really the antenna of the insects which split at the end into four flexible appendages resembling fingers. His mistake is a natural one, for the Mercurians used their antenna as extra arms.--James S. Carpenter.]

The backplates were a brilliant green in color, with six-inch stripes of chrome yellow running lengthwise and crimson spots three inches in diameter arranged in rows between the stripes. Their huge-faceted eyes sparkled like crystal when the light fell on them, and from time to time waves of various colors passed over them, evidently reflecting the insect’s emotions. Although they gave the impression of great muscular power, their movements were slow and sluggish, and they seemed to have difficulty in getting around.

As my horrified gaze took in these monstrosities I turned with a shudder to Jim Carpenter.

“Am I crazy, Jim,” I asked, “or do you see these things too?”

“I see them all right, Pete,” he replied. “It isn’t as surprising as it seems at first glance. You expected to find human beings; so did I, but what reason had we for doing so? It is highly improbable, when you come to consider the matter, that evolution should take the same course elsewhere as it did on earth. Why not beetles, or fish, or horned toads, for that matter?”

“No reason, I guess,” I answered; “I just hadn’t expected anything of the sort. What do you suppose they mean to do with us?”

“I haven’t any idea, old man. We’ll just have to wait and see. I’ll try to talk to them, although I don’t expect much luck at it.”

He turned to the nearest beetle and slowly and clearly spoke a few words. The insect gave no signs of comprehension, although it watched the movement of Jim’s lips carefully. It is my opinion, and Jim agrees with me, that the insects were both deaf and dumb, for during the entire time we were associated with them, we never heard them give forth a sound under any circumstances, nor saw them react to any sound that we made. Either they had some telepathic means of communication or else they made and heard sounds beyond the range of the human ear, for it was evident from their actions that they frequently communicated with one another.