Chapter IX: Prologue (2)

Now they maneuvered the heavy plate till it was resting on that beam; then they released the plate, and watched it slide down the incline, shooting through the open doorway of the car. In moments the job was done. The plate at last safely stowed, the three men climbed into the car, and prepared to leave.

The little machine glided swiftly down the tube through the mighty ship, finally coming out through the opening that had admitted them. They rose quickly into the air, and headed for the headquarters of the government ships.

II

A great number of scientists and military men were already gathered about the headquarters ship. As Arcot's party arrived, they learned that each of the wrecks was being assigned to one group. They further learned that because of their scientific importance, they were to go to the nearly perfect ship lying off to the west. Two Air Patrolmen were to accompany them.

"Lieutenant Wright and Lieutenant Greer will go with you," said the Colonel. "In the event of trouble from possible--though unlikely--survivors, they may be able to help. Is there anything further we can do?"

"These men are armed with the standard sidearms, aren't they?" Arcot asked. "I think we'll all be better off if I arm them with some of the new director-ray pistols. I have several in my boat. It will be all right, I suppose?"

"Certainly, Dr. Arcot. They are under your command."

The party, increased to five now, returned to the ship, where Arcot showed the men the details of the ray pistols, and how to use them. The control for direction of operation was rather intricate in these early models, and required considerable explanation. The theoretical range of even these small hand weapons was infinity in space, but in the atmosphere the energy was rather rapidly absorbed by ionization of the air, and the dispersion of the beam made it ineffective in space over a range of more than thirty-five miles.

Again entering the little molecular motion car, they went at once to the great hull of the fallen ship. They inspected it cautiously from overhead before going too close, for the dreadnought, obviously, had landed without the terrific concussion that the others had experienced, and there was a possibility that some of the crew had survived the crash. The entire stern of the huge vessel had been torn off, and evidently the ship was unable to rise, but there were lights glowing through the portholes on the side, indicating that power had not failed completely.

"I think we'd better treat that monster with respect," remarked Wade, looking down at the lighted windows. "They have power, and the hull is scarcely dented except where the stern was caught by a beam. It's lucky we had those ray projector ships! They've been in service only about four months, haven't they, Lieutenant?"

"Just about that, sir," the Air Patrolman replied. "They hadn't gotten the hand weapons out in sufficient quantities to be issued to us as yet."

Morey scowled at the invader. "I don't like this at all. I wonder why they didn't greet us with some of their beams," he said in worried tones. It did seem that there should be some of the rays in action now. They were less than a mile from the fallen giant, and moving rather slowly.

"I've been puzzled about that myself," commented Arcot, "and I've come to the conclusion that either the ray projectors are fed by a separate system of power distribution, which has been destroyed, or that the creatures from space are all dead."

They were to learn later, in their exploration of the ship, that the invaders' ray projectors were fed from a separate generator, which produced a special form of alternating current wave for them. This generator had been damaged beyond use.

The little machine was well toward the stern of the giant now, and they lowered it till it was on a level with the torn metal. It was plain that the ship had been subjected to some terrific tension. The great girders were stretched and broken, and the huge ribs were bent and twisted. The central tube, which ran the length of the ship, had been drawn down to about three quarters of its original diameter, making it necessary for them to use their ray to enter. In moments their speedster glided into the dark tunnel. The searchlight reaching ahead filled the metal tunnel with a myriad deceptive reflections. The tube was lighted up far ahead of them, and seemed empty. Cautiously they advanced, with Arcot at the controls.

"Wade--Morey--where will we stop first?" he asked. "The engines? They'll probably be of prime importance. We know their location. What do you say?"

"I agree," replied Wade, and Morey nodded his approval.

They ran their craft down the long tube till they reached the door they knew must be the engine room landing, and stepped out, each wearing an altitude suit. This ship had landed level, and progress would be much easier than in the other one. They waited a moment before opening the door into the engine room, for this led into a narrow corridor where only one could pass. Caution was definitely in order. The Air Patrolmen insisted on leading the way. They had been sent along for the express purpose of protecting the scientists, and it was their duty to lead. After a brief argument Arcot agreed.

The two officers stepped to the door, and standing off to one side, tore it open with a ray from their pistols. It fell with a clatter to the rounded metal floor of the tube, and lay there vibrating noisily, but no rays of death lanced out from beyond it. Cautiously they peered around the corner of the long corridor, then seeing nothing, entered. Wade came next, then Arcot, followed by Morey.

The corridor was approximately thirty feet long, opening into the great engine room. Already the men could hear the smooth hum of powerful machines, and could see the rounded backs of vast mechanisms. But there was no sign of life, human or otherwise. They halted finally at the threshold of the engine room.

"Well," Arcot said softly. "We haven't seen anyone so far, and I hope no one has seen us. The invaders may be behind one of those big engines, quite unaware of us. _If_ they're there, and they see us, they'll be ready to fight. Now remember, those weapons you have will tear loose anything they hit, so take it easy. You know something about the power of those engines, so don't put them out of commission, and have them splash us all over the landscape.

"But look out for the crew, and get them if they try to get you!"

Cautiously but quickly they stepped out into the great room, forming a rough half circle, pistols ready for action. They walked forward stealthily, glancing about them--and simultaneously the enemies caught sight of each other. There were six of the invaders, each about seven feet tall, and surprisingly humanoid. They somewhat resembled Venerians, but they weren't Venerians, for their skin was a strange gray-white, suggesting raw dough. It seemed to Arcot that these strange, pale creatures were advancing at a slow walk, and that he stood still watching them as they slowly raised strange hand weapons. He seemed to notice every detail: their short, tight-fitting suits of some elastic material that didn't hamper their movements, and their strange flesh, which just seemed to escape being transparent. Their eyes were strangely large, and the black spot of the pupil in their white corneas created an unnatural effect.

Then abruptly their weapons came up--and Arcot responded with a sudden flick of his ray, as he flung himself to one side. Simultaneously his four companions let their beams fly toward the invaders. They glowed strangely red here, but they were still effective. The six beings were suddenly gone--but not before they had released their own beams. And they had taken toll. Lieutenant Wright lay motionless upon the floor.

The Terrestrians scarcely had a chance to notice this, for immediately there was a terrific rending crash, and clean daylight came pouring in through a wide opening in the wall of the ship. The five rays had not stopped on contact with the enemy, but had touched the wall behind them. An irregular opening now gaped in the smooth metal.

Suddenly there came a second jarring thud, a dull explosion; then a great sheet of flame filled the hole--a wall of ruddy flame swept rapidly in. Arcot swung up his ray pistol, pointing it at the mass of flaming gas. A mighty column of air came through the narrow corridor from the tube, rushing toward the outside, and taking the flame with it. A roaring mass of gas hovered outside of the ship.

"Lieutenant," said Arcot, swiftly, "turn your ray on that hole, and keep it there, blowing that flame outside with it. You'll find you can't put the fire out, but if you keep it outside the ship, I believe we'll be reasonably safe." The Patrolman obeyed instantly, relieving Arcot.

Wade and Morey were already bending over the fallen man.

"I'm afraid there's nothing we can do for him," the latter said grimly, "and every moment here is dangerous. Let's continue our investigation and carry him back to the ship when we leave." Arcot nodded silently.

Solemnly they turned away from the motionless figure on the floor and set out on their investigation.

"Arcot," began Morey after a moment, "why is that gas burning like that? Can't we put it out?"

"Let's get through with this job first," replied Arcot somewhat tersely. "The discussion comes after."

The bodies of the invaders were gone, so they could not examine them now. That was a matter for the doctors and biologists, anyway. The engines were their main interest, huge things which overshadowed everything about them.

It must have been the concealment afforded by the engines that permitted three of the enemy to get so close. The only warning the Terrestrians had was a faint pink haze as they stepped around the corner of an engine; and a sudden feeling of faintness swept over them. They leaped back, out of sight, peering around the corner with nerves and muscles tensed. There was no sign of movement.

As they watched, they saw a pallid hand reaching out with a ray gun; and Wade swiftly pointed his own weapon. There came a sudden crash of metal, a groan and quiet. Two other aliens leaped from behind the great engine just as the Terrestrians dodged further back; as swiftly, they too found concealment.

Arcot swung his ray up, and was about to pull the trigger that would send the huge engine toppling over upon them, when he saw that it was running. He thought of the unknown energies in the machine, the potential destruction, and he shook his head. Cautiously he looked around the edge of the towering mass, waiting--his beam flashed out, and there was a snapping sound as the ray caught a reaching hand and hurled its owner against a mighty transformer of some sort. For an instant the huge mass tottered, then was still. In the low concentration of power that Arcot had used, only a small portion had been touched, and the molecules of this portion had not been enough to tip over its tremendous weight.

Only one enemy remained; and Arcot learned swiftly that he was still in action, for before he could dodge back there came that now-familiar pink haziness. It touched Arcot's hand, outstretched as it had been when he fired, and a sudden numbness came over it. His pistol hand seemed to lose all feeling of warmth or cold. It was there; he could still feel the weapon's deadened weight. Reflex action hurled him back, his hand out of range of the ray. In seconds feeling began to return, and in less than ten his hand was normal again.

He turned to the others with a wry grin. "Whew--that was a narrow squeak! I must say their ray is a gentlemenly sort of thing. It either kills you, or doesn't injure you at all. There it goes again!"

A shaft of pink radiance reached the end of the engine, just grazing it, evidently absorbed by its mass. "Pinning us down," Wade grated. They certainly couldn't step out into the open space--but they couldn't stay where they were indefinitely, either. Reinforcements might arrive!

"Look," Wade pointed with his pistol, "he's under that big metal bar--up there in the roof--see it? I'll pull it down; he may get nervous and come into sight." Swiftly Arcot sprang forward and caught his arm.

"Lord--don't do that, Wade--there's too much stuff here that we don't know anything about. Too much chance of your smashing us with him. I'm going to try to get around to the other side of this machine and see what I can do, while you fellows keep him occupied."

Arcot disappeared around the black humming giant. Interminably the others waited for something to happen; then suddenly the beam that had been playing at irregular intervals across the end of the machine, swung quickly to the other side; and simultaneously another ray seemed to leap from the machine itself. They met and crossed. There came a momentary crashing arc, then both went dead, as the apparatus that generated them blew out under terrific overload.

The invader evidently carried a spare, for the watchers saw him dart from concealment, clawing at his pocket pouch. They turned their rays on him, and just as his projector came free, a ray hurled him violently to the left. He crashed into a huge motor, and the result was not nice.

The projector had been jerked from his hand and lay off to the side. Arcot ran to it and picked it up just as they heard the Lieutenant call an alarmed inquiry.

"I think we're okay now," Arcot answered. "I hope there are no more--but by all means stay where you are, and use as little power as possible in blowing that flame outside. It uses up the atmosphere of the ship, and though we don't need it, I think we'd better take things easy. Call us if anything looks odd to you."

For several minutes the three scientists looked about them in awe-struck wonder. They were the first men of Earth to see the driving equipment of one of the tremendous Kaxorian planes, and they felt tiny beside its great bulk; but now, as they examined this engine room, they realized that even the huge plane shrank into insignificance beside this interstellar cruiser.

All about them loomed the great rounded backs of giant electric motor-generators of some sort. Across the roof ran a network of gigantic metal bars, apparently conductors, but so large that they suggested heavy structural members. The machines they ran into loomed fully thirty feet into the air; they were longer than cylinders, thirty feet in diameter, and there was a group of four main machines fully a hundred twenty feet long! There were many smaller mechanisms--yet these smaller ones would easily have constituted a complete power supply for the average big city. Along each wall ran a bank of transformers, cast in the same heroic mold. These seemed connected with the smaller machines, there being four conductors leading into each of the minor units, two intake, and two, apparently, output leads, suggesting rotary converters. The multiple units and the various types and sizes of transformers made it obvious that many different frequencies were needed. Some of the transformers had air cores, and led to machines surrounded with a silvery white metal instead of the usual iron. These, apparently, were generating current at an extremely high frequency.

"Well," Morey commented, "they ought to have power enough. But do you notice that those four main units have their leads radiating in different directions? The one on the left there seems to lead to that big power board at the front--or better, bow. I think it would be worth investigating."

Arcot nodded. "I had the same idea. You notice that two of the main power units are still working, but that those other two have stopped? Probably the two dead ones have something to do with the motion of the ship. But there's one point I think is of even greater interest. All the machines we have seen, all the conspicuous ones, are secondary power sources. There are no primary sources visible. Notice that those two main conduits lead over to the right, and toward the bow. Let's check where they go to."

As they talked they followed the huge conductors back to their point of convergence. Suddenly they rounded one of the huge main power units, and saw before them, at the center of square formed by these machines, a low platform of transparent light-metal. At the exact center of this platform, which was twenty feet in diameter, there was a table, about seven feet across and raised about five feet above the level of the platform on stout light-metal legs. On the table were two huge cubes of solid silver, and into these cubes ran all the conductors they had seen.

In the space of about six inches left between the blocks of metal, there was a small box constructed of some strange new material. It was the most perfect reflecting surface that any of the men had ever imagined. Indeed, it was so perfect a reflector that they were unable to see it, but could detect its presence only by the mirror images, and the fact that it blotted out objects behind it.

Now they noticed that through the huge blocks of metal there were two small holes, and two thin wires of this same reflecting material led into those holes. The wires led directly up to the roof, and, suspended on three-foot hangers of the light-metal, continued on toward the bow.

Could this be the source of power for the entire ship? It seemed impossible, yet there were many other seeming impossible things here, among them that strangely reflecting matter.

There was a low railing about the central platform, apparently intended to keep observers at a safe distance, so they decided against any more detailed investigation. As they were about to discuss their unusual find, the Lieutenant called that he heard sounds behind him.

At once the three ran rapidly toward the narrow corridor that had given them entrance. The flaming gas was still shooting through the hole in the wall of the ship, and the rush of air through the corridor made it difficult to hear any sounds there, and exceedingly difficult to walk.

"Turn on more power, Lieutenant, and see if we can't draw out the enemy," suggested Arcot, while they braced themselves around the tube exit.

As the Patrolman increased the power of his beam, the moan of the air through the corridor increased suddenly to a terrific roar, and a cyclonic gale swept through. But none of the invaders were drawn out.

After the Lieutenant had shut off the blast from his pistol at Arcot's signal, the latter said: "I don't think anything less than a war tank could stand that pressure. It's probable that we'll be attacked if we stay here much longer, though--and we may not be able to get out at all. I think, Lieutenant, I'll ask you to stay here while we go out and get the ship ready to leave." He paused, grinning. "Be sure to keep that flame outside. You'll be in the position of Hercules after Atlas left him holding the skies on his shoulders. You can't shut off the ray for long or we'll have a first-rate explosion. We'll signal when we're ready by firing a revolver, and you make it to the ship as fast as you can travel."

Arcot's expression became solemn. "We'll have to carry Wright back to the ship. He was a brave man, and he certainly deserves burial in the soil of his own world. And, Morey, we'll have to look up his family. Your father's company will have to take care of them if they need help."

Slowly the men forced their way back toward their ship, fighting against the roaring column of air, their burden hindering them somewhat; but at last they reached the open tunnel. Even here the air was in violent motion.

They got into their boat as quickly as possible, and set the controls for reverse flight. Then Wade fired the signal shot. In moments they saw Lieutenant Greer bucking against the current of air, continuing under its own momentum.

By the time he was in the ship an ominous calm had fallen. Swiftly they sped down the corridor, and had almost reached the open air, when suddenly there was a dull rumble behind them, and they were caught on a wave of pressure that hurled them along at terrific speed. In a flash they sped into the open air, the great tunnel with its thick walls and flared opening acting like a gigantic blunderbus, with the ship as its bullet. Arcot made no attempt to slow down the little craft, but pressed his foot heavily on the vertical accelerator. The ship rocketed up with terrific speed, and the acceleration pinned the men down to their seats with tripled weight.

Anxiously they watched the huge invader as they sped away from it. At Arcot's direction Morey signaled the other groups of scientists to get out of danger with all speed, warning of the impending blow-up. As the moments sped by the tension mounted. Arcot stared fixedly into the screen before him, keeping the giant space ship in focus. As they sped mile upon miles away from it, he began to relax a bit.

Not a word was spoken as they watched and waited. Actually, very little time passed before the explosion, but to the watchers the seconds dragged endlessly. Then at twenty-seven miles, the screen flared into a sheet of blinding white radiance. There was a timeless instant--then a tremendous wave of sound, a roaring, stunning concussion smote the ship, shaking it with unrestrained fury--to cease as abruptly as it came.

Immediately they realized the reason. They were rushing away from the explosion faster than the sound it made, hence could not hear it. After the first intolerable flash, details became visible. The great ship seemed to leap into countless tremendous fragments, each rushing away from the point of the blow-up. They did not go far; the force was not sustained long enough, nor was it great enough to overcome the inertia of so vast a mass for more than moments. Huge masses rained to earth, to bury themselves in the soil.

There came a momentary lull. Then suddenly, from the mass which evidently held the wrecked engine room, there shot out a beam of intense white light that swept around in a wide, erratic arc. Whatever it touched fused instantly into a brilliantly glowing mass of liquid incandescence. The field itself, fragments of the wreckage, fused and mingled under its fury. The beam began to swing, faster and faster, as the support that was holding it melted; then abruptly it turned upon itself. There came a sudden blast of brilliance to rival that of the sun--and the entire region became a molten lake. Eyes streaming, temporarily blinded, the men turned away from the screen.

"That," said Arcot ruefully, "is that! It seems that our visitors don't want to leave any of their secrets lying around for us to investigate. I've an idea that all the other wrecks will go like this one did." He scowled. "You know, we really didn't learn much. Guess we'd better call the headquarters ship and ask for further instructions. Will you attend to it, Lieutenant Greer?"

III

Swiftly Arcot's sleek cruiser sped toward New York and the Arcot Laboratories. They had halted briefly at the headquarters ship of the Earth-Venus forces to report on their experience; and alone again, the three scientists were on their way home.

With their course set, Arcot spoke to the others. "Well, fellows, what are your opinions on--what we've seen? Wade, you're a chemist--tell us what you think of the explosion of the ship, and of the strange color of our molecular ray in their air."

Wade shook his head doubtfully. "I've been trying to figure it out, and I can't quite believe my results. Still, I can't see any other explanation. That reddish glow looked like hydrogen ions in the air. The atmosphere was certainly combustible when it met ours, which makes it impossible for me to believe that their air contained any noticeable amount of oxygen, for anything above twenty per cent oxygen and the rest hydrogen would be violently explosive. Apparently the gas had to mix liberally with our air to reach that proportion. That it didn't explode when ionized, showed the absence of hydro-oxygen mixture.

"All the observed facts except one seem to point to an atmosphere composed largely of hydrogen. That one--there are beings living in it! I can understand how the Venerians might adapt to a different climate, but I can't see how anything approaching human life can live in an atmosphere like that."

Arcot nodded. "I have come to similar conclusions. But I don't see too much objection to the thought of beings living in an atmosphere of hydrogen. It's all a question of organic chemistry. Remember that our bodies are just chemical furnaces. We take in fuel and oxidize it, using the heat as our source of power. The invaders live in an atmosphere of hydrogen. They eat oxidizing fuels, and breathe a reducing atmosphere; they have the two fuel components together again, but in a way different from our method. Evidently, it's just as effective. I'm sure that's the secret of the whole thing."

"Sounds fairly logical." Wade agreed. "But now I have a question for you. Where under the sun did these beings come from?"

Arcot's reply came slowly. "I've been wondering the same thing. And the more I wonder, the less I believe they did come from--under our sun. Let's eliminate all the solar planets--we can do that at one fell swoop. It's perfectly obvious that those ships are by no means the first crude attempts of this race to fly through space. We're dealing with an advanced technology. If they have had those ships even as far away as Pluto, we should certainly have heard from them by now.

"Hence, we've got to go out into interstellar space. You'll probably want to ram some of my arguments down my throat--I know there is no star near enough for the journey to be made in anything less than a couple of generations by all that's logical; and they'd freeze in the interstellar cold doing it. There is no _known_ star close enough--but how about unknowns?"

"What have they been doing with the star?" Morey snorted. "Hiding it behind a sun-shade?"

Arcot grinned. "Yes. A shade of old age. You know a sun can't radiate forever; eventually they die. And a dead sun would be quite black, I'm sure."

"And the planets that circle about them are apt to become a wee bit cool too, you know."

"Agreed," said Arcot, "and we wouldn't be able to do much about it. But give these beings credit for a little higher order of intelligence. We saw machines in that space ship that certainly are beyond us! They are undoubtedly heating their planets with the same source of energy with which they are running their ships.

"I believe I have confirmation of that statement in two things. They are absolutely colorless; they don't even have an opaque white skin. Any living creature exposed to the rays of a sun, which is certain to emit some chemical rays, is subject to coloration as a protection against those rays. The whites, who have always lived where sunlight is weakest, have developed a skin only slightly opaque. The Orientals, who live in more tropical countries, where less clothes and more sun is the motto, have slightly darker skins. In the extreme tropics Nature has found it necessary to use a regular blanket of color to stop the rays. Now extrapolating the other way, were there no such rays, the people would become a pigmentless race. Since most proteins are rather translucent, at least when wet, they would appear much as these beings do. Remember, there are very few colored proteins. Hemoglobin, such as in our blood, and hemocyanin, like that in the blue blood of the Venerians, are practically unique in that respect. For hydrogen absorption, I imagine the blood of these creatures contains a fair proportion of some highly saturated compound, which readily takes on the element, and gives it up later.

"But we can kick this around some more in the lab."

Before starting for New York, Arcot had convinced the officer in charge that it would be wise to destroy the more complete of the invaders' ships at once, lest one of them manage to escape. The fact that none of them had any rays in operation was easily explained; they would have been destroyed by the Patrol if they had made any show of weapons. But they might be getting some ready, to be used in possible escape attempts. The scientists were through with their preliminary investigations. And the dismembered sections would remain for study, anyway.

The ships had finally been rayed apart, and when the three had left, their burning atmosphere had been sending mighty tongues of flame a mile or more into the air. The light gas of the alien atmosphere tended to rise in a great globular cloud, a ball that quickly burned itself out. It had not taken long for the last of the machines to disintegrate under the rays. There would be no more trouble from them, at any rate!

Now Morey asked Arcot if he thought that they had learned all they could from the ships; would it not have been wiser to save them, and investigate more fully later, taking a chance on stopping any sudden attack by surviving marauders by keeping a patrol of Air Guards there.

To which Arcot replied, "I thought quite a bit before I suggested their destruction, and I conferred for a few moments with Forsyth, who's just about tops in biology and bacteriology. He said that they had by no means learned as much as they wished to, but they'd been forced to leave in any event. Remember that pure hydrogen, the atmosphere we were actually living in while on the ship, is quite as inert as pure oxygen--when alone. But the two get very rough when mixed together. The longer those ships lay there the more dangerously explosive they became. If we hadn't destroyed them, they would have wrecked themselves. I still think we followed the only logical course.

"Dr. Forsyth mentioned the danger of disease. There's a remote possibility that we might be susceptible to their germs. I don't believe we would be, for our chemical constitution is so vastly different. For instance, the Venerians and Terrestrians can visit each other with perfect freedom. The Venerians have diseases, and so do we, of course; but there are things in the blood of Venerians that are absolutely deadly to any Terrestrian organism. We have a similar deadly effect on Venerian germs. It isn't immunity--it's simply that our respective constitutions are so different that we don't need immunity. Similarly, Forsyth thinks we would be completely resistant to all diseases brought by the invaders. However, it's safer to remove the danger, if any, first, and check afterward."

The three men sped rapidly back to New York, flying nearly sixty miles above the surface of the Earth, where there would be no interfering traffic, till at length they were above the big city, and dropping swiftly in a vertical traffic lane.

Shortly thereafter they settled lightly in the landing cradle at the Arcot Laboratories. Arcot's father, and Morey's, were there, anxiously awaiting their return. The elder Arcot had for many years held the reputation of being the nation's greatest physicist, but recently he had lost it--to his son. Morey Senior was the president and chief stockholder in the Transcontinental Air Lines. The Arcots, father and son, had turned all their inventions over to their close friends, the Moreys. For many years the success of the great air lines had been dependent in large part on the inventions of the Arcots; these new discoveries enabled them to keep one step ahead of competition, and as they also made the huge transport machines for other companies, they drew tremendous profits from these mechanisms. The mutual interest, which had begun as a purely financial relationship, had long since become a close personal friendship.

As Arcot stepped from his speedster, he called immediately to his father, telling of their find, the light-matter plate.

"I'll need a handling machine to move it. I'll be right back." He ran to the elevator and dropped quickly to the heavy machinery lab on the lower floor. In a short time he returned with a tractor-like machine equipped with a small derrick, designed to get its power from the electric mains. He ran the machine over to the ship. The others looked up as they heard the rumble and hum of its powerful motor. From the crane dangled a strong electro-magnet.

"What's that for?" asked Wade, pointing to the magnet. "You don't expect this to be magnetic, do you?"

"Wait and see!" laughed Arcot, maneuvering the handling machine into position. One of the others made contact with the power line, and the crane reached into the ship, lowering the magnet to the plate of crystal. Then Arcot turned the power into the lifting motor. The hum rose swiftly in volume and pitch till the full load began to strain the cables. The motor whined with full power, the cables vibrating under the tension. The machine pulled steadily, until, to Arcot's surprise, the rear end of the machine rose abruptly from the floor, tipping forward.

"Well--it _was_ magnetic, but how did you know?" asked the surprised Wade. Since the ship was made of the Venerian metal, coronium, which was only slightly magnetic, the plate was obviously the magnet's only load.

"Never mind. I'll tell you later. Get an I-beam, say about twenty feet long, and see if you can't help lift that crazy mass. I think we ought to manage it that way."

And so it proved. With two of them straddling the I-beam, the leverage was great enough to pull the plate out. Running it over to the elevator, they lowered the heavy mass, disconnected the cable, and rode down to Arcot's laboratory. Again the I-beam and handling machine were brought into play, and the plate was unloaded from the car. The five men gathered around the amazing souvenir from another world.

"I'm with Wade in wondering how you knew the plate was magnetic, son," commented the elder Arcot. "I can accept your explanation that the stuff is a kind of matter made of light, but I know you too well to think it was just a lucky guess. How did you know?"

"It really was pretty much of a guess, Dad, though there was some logic behind the thought. You ought to be able to trace down the idea! How about you, Morey?" Arcot smiled at his friend.

"I've kept discreetly quiet," replied Morey, "feeling that in silence I could not betray my ignorance, but since you ask me, I can guess too. I seem to recall that light is affected by a powerful magnet, and I can imagine that that was the basis for your guess. It has been known for many years, as far back as Clerk Maxwell, that polarized light can be rotated by a powerful magnet."

"That's it! And now we may as well go over the whole story, and tell Dad and your father all that happened. Perhaps in the telling, we can straighten out our own ideas a bit."

For the next hour the three men talked, each telling his story, and trying to explain the whys and wherefores of what he had seen. In the end all agreed on one point: if they were to fight this enemy, they _must_ have ships that could travel though space with speed to match that of the invaders, ships with a self-contained source of power.

During a brief lull in the conversation, Morey commented rather sarcastically: "I wonder if Arcot will now kindly explain his famous invisible light, or the lost star?" He was a bit nettled by his own failure to remember that a star could go black. "I can't see what connection this has with their sudden attack. If they were there, they must have developed when the star was bright, and as a star requires millions of years to cool down, I can't see how they could suddenly appear in space."

Before answering, Arcot reached into a drawer of his desk and pulled out an old blackened briar pipe. Methodically he filled it, a thoughtful frown on his face; then carefully lighting it, he leaned back, puffing out a thin column of gray smoke.

"Those creatures must have developed on their planets before the sun cooled." He puffed slowly. "They are, then, a race millions of years old--or so I believe. I can't give any scientific reason for this feeling; it's merely a hunch. I just have a feeling that the invaders are old, older than our very planet! This little globe is just about two billion years old. I feel that that race is so very ancient they may well have counted the revolutions of our galaxy as, once every twenty or thirty million years, it swung about its center.

"When I looked at those great machines, and those comparatively little beings as they handled their projectors, they seemed out of place. Why?" He shrugged. "Again, just a hunch, an impression." He paused again, and the slow smoke drifted upward.

"If I'm granted the premise that a black, dead star is approaching the Solar System, then my theorizing may seem more logical. You agree?" The listeners nodded and Arcot continued. "Well--I had an idea--and when I went downstairs for the handling machine, I called the Lunar Observatory." He couldn't quite keep a note of triumph out of his voice. "Gentlemen--some of the planets have been misbehaving! The outermost planets, and even some of those closer to the sun have not been moving as they should. A celestial body of appreciable mass _is_ approaching the System; though thus far nothing has been seen of the visitor!"

A hubbub of excited comment followed this startling revelation. Arcot quieted them with an upraised hand. "The only reason you and the world at large haven't heard about this as yet is the fact that the perturbation of the planets is so very slight that the astronomers figured they might have made an error in calculation. They're rechecking now for mistakes.

"To get back to my visualization--It must have been many millions of years ago that life developed on the planets of the black star, a warm sun then, for it was much younger. It was probably rather dim as suns go even its younger days. Remember, our own sun is well above average in brilliance and heat radiation.

"In those long-gone ages I can imagine a race much like ours developing, differing chemically, in their atmosphere of hydrogen; but the chemical body is not what makes the race, it's the thought process. They must have developed, and then as their science grew, their sun waned. Dimmer and dimmer it became, until their planets could not maintain life naturally. Then they had to heat them artificially. There is no question as to their source of power; they had to use the energy of matter--so called atomic energy--for no other source would be great enough to do what had to be done. It is probable that their science had developed this long before their great need arose.

"With this must also have come the process of transmutation, and the process they use in driving their interstellar cruisers. I am sure those machines are driven by material energy.

"But at last their star was black, a closed star, and their cold, black planets must circle a hot, black sun forever! They were trapped for eternity unless they found a way to escape to some other stellar system. They could not travel as fast as light, and they could escape only if they found some near-by solar system. Their star was dead--black. Let's call it Nigra--the Black One--since like every other star it should have a name. Any objection?"

There was none, so Arcot continued:

"Now we come to an impossibly rare coincidence. That two suns in their motion should approach each other is beyond the point of logic. That both suns have a retinue of planets approaches the height of the ridiculous. Yet that is what is happening right now. And the Nigrans--if that's the correct term--have every intention of taking advantage of the coincidence. Since our sun has been visible to them for a long, long time, and the approaching proximity of the suns evident, they had lots of time to prepare.

"I believe this expedition was just an exploratory one; and if they can send such huge machines and so many of them, for mere exploration, I'm sure they must have quite a fleet to fight with.

"We know little about their weapons. They have that death ray, but it's not quite as deadly as we might have feared, solely because our ships could outmaneuver them. Next time, logically, they'll bring with them a fleet of little ships, carried in the bellies of those giants, and they'll be a real enemy. We'll have to anticipate their moves and build to circumvent them.

"As for their ray, I believe I have an idea how it works. You're all familiar with the catalytic effects of light. Hydrogen and chlorine will stand very peacefully in the same jar for a long time, but let a strong light fall on them, and they combine with terrific violence. This is the catalytic effect of a vibration, a wave motion. Then there is such a thing as negative catalysis. In a certain reaction, if a third element or compound is introduced, all reaction is stopped. I believe that's the principle of the Nigran death ray; it's a catalyst that simply stops the chemical reactions of a living body, and these are so delicately balanced that the least resistance will upset them."

Arcot halted, and sat puffing furiously for a moment. During his discourse the pipe had died to an ember; with vigorous puffing he tried to restore it. At last he had it going and continued.

"What other weapons they have we cannot say. The secret of invisibility must be very old to them. But we'll guard against the possibility by equipping our ships against it. The only reason the patrol ships aren't equipped already is that invisibility is useless with modern criminals; they all know the secret and how to fight it."

Morey interrupted with a question.

"Arcot, it's obvious that we have to get out into space to meet the enemy--and we'll have to have freedom of movement there. How are we going to do it? I was wondering if we could use Wade's system of storing the atomic hydrogen in solution. That yields about 100,000 calories for every two grams, and since this is a method of storing heat energy, and your molecular motion director is a method of converting heat into mechanical work with 100 per cent efficiency, why not use that? All we need, really, is a method of storing heat energy for use while we're in space."

Arcot exhaled slowly before answering, watching the column of smoke vanish into the air.

"I thought of that, and I've been trying to think of other, and if possible, better, cheaper, and quicker ways of getting the necessary power.

"Let's eliminate the known sources one by one. The usual ones, the ones men have been using for centuries, go out at once. The atomic hydrogen reaction stores more energy per gram than any other chemical reaction known. Such things as the storage battery, the electro-static condenser, the induction coil, or plain heat storage, are worthless to us. The only other method of storing energy we know of is the method used by the Kaxorians in driving their huge planes.

"They use condensed light-energy. This is efficient to the ultimate maximum, something no other method can hope to attain. Yet they need huge reservoirs to store it. The result is still ineffective for our purpose; we want something we can put in a small space; we want to condense the light still further. That will be the ideal form of energy storage, for then we will be able to release it directly as a heat ray, and so use it with utmost efficiency. I think we can absorb the released energy in the usual cavity radiator."

A queer little smile appeared on Arcot's face. "Remember--what we want is light in a more condensed form, a form that is naturally stable, and that does not need to be held in a bound state, but actually requires urging to bring about the release of energy. For example--"

A shout from Wade interrupted him. "That's really rare! _Whoo_--I have to hand it to you! That takes all the prizes!" He laughed delightedly. In puzzled wonder Morey and the two older men looked at him, and at Arcot who was grinning broadly now.

"Well, I suppose it must be funny," Morey began, then hesitated. "Oh--I see--say, that _is_ good!" He turned to his father. "I see now what he's been driving at. It's been right here under our noses all the time.

"The light-matter windows we found in the wrecked enemy ships contain enough bound light-energy to run all the planes we could make in the next ten years! We're going to have the enemy supply us with power we can't get in any other way. I can't decide, Arcot, whether you deserve a prize for ingenuity, or whether we should receive booby-prizes for our stupidity."

Arcot Senior smiled at first, then looked dubiously at his son.

"There's definitely plenty of the right kind of energy stored there--but as you suggested, the energy will need encouragement to break free. Any ideas?"

"A couple. I don't know how they'll work, of course; but we can try." Arcot puffed at his pipe, serious now as he thought of the problems ahead.

Wade interposed a question. "How do you suppose they condense that light energy in the first place, and, their sun being dead, whence all the light? Back to the atom, I suppose."

"You know as much as I do, of course, but I'm sure they must break up matter for its energy. As for the condensation problem, I think I have a possible solution of that too--it's the key to the problem of release. There's a lot we don't know now--but we'll have a bigger store of knowledge before this war is over--if we have anything at all!" he added grimly. "It's possible that man may lose knowledge, life, his planets and sun--but there's still plenty of hope. We're not finished yet."

"How do you think they got their energy loose?" asked

Wade. "Do you think those big blocks of what appeared to be silver were involved in the energy release?"

"Yes, I do. Those blocks were probably designed to carry away the power once it was released. How the release was accomplished, though, I don't know. They couldn't use material apparatus to start their release of material energy; the material of the apparatus might 'catch fire' too. They had to have the disintegrating matter held apart from all other matter. This was quite impossible, if you are going to get the energy away by any method other than by the use of fields of force. I don't think that is the method. My guess is that a terrific current of electricity would accomplish it if anything would.

"How then are we going to get the current to it? The wires will be subject to the same currents. Whatever they do to the matter involved, the currents will do to the apparatus--except in one case. If that apparatus is made of _some other kind of matter_, then it wouldn't be affected. The solution is obvious. Use some of the light-matter. What will destroy light-matter, won't destroy electricity-matter, and what will destroy electricity-matter, won't disturb light-matter.

"Do you remember the platform of light-metal, clear as crystal? It must have been an insulating platform. What we started as our assumptions in the case of the light-metal, we can now carry further. We said that electricity-metals carried electricity, so light-metals would carry or conduct light. Now we know that there is no substance which is transparent to light, that will carry electricity by metallic conduction. I mean, of course, that there is no substance transparent to light, and at the same time capable of carrying electricity by electronic transmission. True, we have things like NaCl solutions in ordinary H_{2}O which will carry electricity, but here it's ionic conduction. Even glass will carry electricity very well when hot; when red hot, glass will carry enough electricity to melt it very quickly. But again, glass is not a solid, but a viscous liquid, and it is again carried by ionic conduction. Iron, copper, sodium, silver, lead--all metals carry the current by means of electron drift through the solid material. In such cases we can see that no transparent substance conducts electricity.

"Similarly, the reverse is true. No substance capable of carrying electricity by metallic conduction is transparent. All are opaque, if in any thickness. Of course, gold is transparent when in leaf form--but when it's that thin it won't conduct very much! The peculiar condition we reach in the case of the invisible ship is different. There the effects are brought about by the high frequency impressed. But you get my point.

"Do you remember those wires that we saw leading to that little box of the reflecting material? So perfectly reflecting it was that we didn't see it. We only saw where it must be; we saw the light it reflected. That was no doubt light-matter, a non-metal, and as such, non-conductive to light. Like sulphur, an electric non-metal, it reflected the base of which it was formed. Sulphur reflects the base of which it was formed. Sulphur reflects electricity and--in the crystalline form--passes light. This light-non-metal did the same sort of thing; it reflected light and passed electricity. It was a conductor.

"Now we have the things we need, the matter to disintegrate, and the matter to hold the disintegrating material in. We have two different types of matter. The rest is obvious--but decidedly not easy. They have done it, though; and after the war is over, there should be many of their machines drifting about in space waiting to give up their secrets."

Arcot Senior clapped his son on the back. "A fair foundation on which to start, anyway. But I think it's time now that you got working on your problem; and since I'm officially retired, I'm going downstairs. You know I'm working in my lab on a method to increase the range and power of your projector for the molecular motion field. Young Norris is helping me, and he really has ideas. I'll show you our math later."

The party broke up, the three younger men staying in their own labs, the older men leaving.

IV

The three immediately set to work. At Arcot's suggestion, Wade and Morey attacked the plate of crystal in an attempt to tear off a small piece, on which they might work. Arcot himself went into the televisophone room and put through a second call to the Tychos Observatory, the great observatory that had so recently been established on the frigid surface of the Moon. The huge mirror, twenty feet in diameter, allowed an immense magnification, and stellar observations were greatly facilitated, for no one bothered them, and the "seeing" was always perfect.

However, the great distance was rather a handicap to the ordinary televisophone stations, and all calls put through to the astronomers had to be made through the powerful sending station in St. Louis, where all interplanetary messages were sent and received, while that side of the Earth was facing the station; and from Constantinople, when that city faced the satellite. These stations could bridge the distance readily and clearly.

For several minutes Arcot waited while connections were being made with the Moon; then for many more minutes he talked earnestly with the observer in this distant station, and at last satisfied, he hung up.

He had outlined his ideas concerning the black star, based upon the perturbation of the planets; then he had asked them to investigate the possibilities, and see if they could find any blotting out of stars by a lightless mass.

Finally he returned to Morey and Wade who had been working on the crystal plate. Wade had an expression of exasperation on his face, and Morey was grinning broadly.