Stranded on a desolate globe, two scientists probe the unknown and harness the super-forces of nature!

Chapter I

The Missing Space Ships

DEAN NORDEN turned restlessly and looked out of the thermalite window, out over Tarragoon. There was an unaccustomed, tense hush over the city, a hush made up of shuffling feet, murmuring voices, and the low, muffling reverberation from the Dome.

And over all, through all, pierced the keen, high shriek of the wind. The shrieking, dancing. wind, that ruffled the intensely blue Lake Tarragoon and whirled the misty spume from Tarragoon Falls in whipped spray. The Falls that were a tiny trickle now, as every last, available bit was sucked from the tiny stream, the only practicable source of power on the whole planet of Pluto.

Norden looked at the tiny bright star that was the setting sun, and shivered. It was cold. So cold out there, that the whole System used it as the expression of ultimate cold. Cold as Pluto.

The murmuring voices of the men in the room interrupted his thoughts. Pilot Commander Horensen was speaking in his heavy, stolid voice, flapping the thick leather gauntlets in his right hand rhythmically against the back of his left.

"I am not so sure it's a good idea," he said. "I'd hate to leave." He shook his head, dark with the sun the Minor planets knew.

"We should send word," said President Bankill. Earth must know what has happened-or what has not happened."

Horensen looked at him thoughtfully. "Yes. But why send a ship? How do you know anything is wrong, anyway?"

Bankill gestured despairingly.

"We know that—know it altogether too well. five weeks ago, Miller's ship was supposed to have arrived. Three weeks ago, Grant Barlom's ship was due. He isn't here yet. One week ago, Dave Garner was due. And he isn't here yet! Three supply ships missing. On Earth trains can be late, freight planes can be late. But in interplanetary schedules they just don't arrive late. They arrive on time or—they don't arrive. You know that better than I.

"Pluto has missed three power-supply ships," Bankill repeated. "There's no sense waiting; we must send word to Earth. It will do no real good, to most of us, of course."

Norden grunted.

"About one thousand of our two and a half million people could be supported here in Tarragoon Dome by the power from Tarragoon Falls. But we must have power for two and a hall million people-for three months. It would take two years for Horensen to reach Earth. He'd have to race some three billion miles at sixty miles a second. Then, four years from now—a ship might get out here!"

Bankill stood up and looked at Horensen with genuine pain in his eyes.

"It is our duty, Horensen, to send you and your men back in the rocket. We belong here. We picked this place. We can't ask you to remain here."

"Damned cold place, this," said Horensen amiably. "It's like Norway in the winter. I like it. You Devil's are a game bunch. We're not walking out—if you don't mind."

"You and your men belong to Interplanetary Service," Bankill pursued. "We have no right to planet you here, rob you of your chance. And, if you stay longer, we will not be able to let you go. Your reserve power will be too valuable to us."

"Chief Mate Garrison is pretty good," said Horensen. "He can take my ship back. I'll stay here."

"You have every right to make your choice, Pilot Horensen," sighed Bankill.

"But I fear we can offer you little hospitality. Pluto is rich in human character, but more poverty-stricken in resources than even you can know, Pilot."

Horensen's gloves flapped dismally as he nodded slowly. "Ja. Ja. Pluto is not so rich in some things. But she has damned good men—real men. I like them."

BANKILL looked at the big-trained Norseman. Slowly a smile spread over his tired face.

"I thank you, Pilot Horensen. We need such men as you here, in times like these. But even your type can do little when such things as the fixed radiation of the sun and the laws of celestial mechanics decree simply and finally that there cannot be but a trickle of heat on this frozen planet."

Bankill bit his lips, went on.

"I wonder if you fully realize that however we may fool ourselves, we are inevitably doomed. Life is an impossibility when food, air, and warmth are absolutely dependent on the arrival of no-longer-existent supply ships."

The Norseman nodded sagely.

"I still stick with you, it you don't mind."

"Yes. I suppose we have s reputation on the Minors for toughness in hanging on to life. But we can't do miracles. Three supply ships gone. Only three months power reserve, with every factory and plant shut down. The supply is cut oh', and without it-the Lord of this planet of Outer Darkness must claim us. Inevitably. If you can get around that-we can't."

"Have you any good rivers?" Horensen asked.

"Rivers! Rivers of liquid nitrogen. That Tarragoon River is the biggest in all equatorial Pluto. The biggest on the planet is the New Yukon, and even little Caesmatite City can't get enough power out oi that flat-country stream to light the dome. You know yourself we've tried. Good Lord, we don't enjoy paying the terrific freight bill for having those thousands of tons of accumulator stacks hauled clear from the Minor planets—Earth, Venus, and Mars-out to here.

"There simply isn't another source on Pluto. In the polar regions there aren't even little streams, for the temperature there is so low that nitrogen freezes, even now, when it is summer. Dean Norden, our foremost engineer-physicist, has just been reporting his findings."

"The thing is utterly hopeless," said Norden. "This is truly the planet of the Lord of Outer Darkness, Horensen."

"Yes," grinned the Norseman? "but you're all his little 'Devils.' Look. That wind out there looks strong enough for something."

The wind was ruffling the lake into little, white-capped waves of liquid nitrogen. Norden looked at it sourly.

"No luck, old man. The atmosphere is mostly hydrogen, nitrogen in slight amount about like water vapor on Earth, helium and neon. Its pressure is only seven pounds-any wind machine would have to be too big. We can't build machinery now."

"Yes, I thought so. You're all a bunch of fools to live out here. But I'll stay here. Mighty interesting to an old Norseman."

Norden laughed in a strained voice.

"I wish I had your confidence. I'm afraid—"

An official entered.

"Toggarty at Number Seven lock, reports a machine from Farnworth, with fifty-seven women and children. They want to enter the Dome," he reported. "Shall we give them permission to bring their men along, too? They want to know."

Bankill shivered, and put his face in his hands.

"Good God, I would have to be president right now. Is that all they said?"

"There are fifteen more women coming in the next machine. The say seven of the older women wouldn't leave Farnworth."

What'll we do, Norden?

"Passamock is the next largest dome. Big domes are more efficient. You'd better send out orders to all small domes to ship every body and all food and power stacks to Passamock or here."

"Why the big domes? They take a lot of power to heat, too."

"Big domes have less radiating area for cubic content," replied Norden. "The thermalite domes material is practically opaque to heat transmission, practically a non-conductor of heat, though transparent to light. But it still radiates. That's my advice, based on radiation physics."

"Let them in, Martell, and tell them to send for their men. Thank you, Dr. Norden.

PRESIDENT BANKILL clenched his fists.

"Horensen, what in God's name has happened to those ships?" he cried.

"I told you, Mr. President, I don't know. We don't ever know in space. The sun-static doesn't let us. Traveling sixty miles a second two weeks apart, we can't communicate very well. Then, it's the sun-spots. Maybe the ships hit an asteroid. Maybe they got wrecked only a few days out from Earth.

Maybe it happened two years ago. Maybe a few weeks ago."

"I rather think it must have been nearly a year ago, or even more," said Norden. "There isn't much after you get past Jupiter. At that time Jupiter was well around in his orbit, too, as he is now. Saturn—Uranus—Neptune. They are nothing—so very far apart. All Majors, too. It happened near the Minors, I think."

"Then the shadow of Death has been hanging over us for more than a year," said Bankill. "What is the shadow, Norden?"

"I don't know, Mr. Bankill. I will guess. I think it is conscious, intelligent, whatever it is. Pirates, even. Though I can't conceive of pirates so utterly inhuman as to condemn a planet to death in this way. They

would certainly let some ships through."

"Pirates. Why? What would they pirate beyond a quantity of energy having value only here, because of our location?"

"Pirates attacking the rich Earth-Mars lines, perhaps," offered Nordea. "They

would require energy to operate, which energy, they, as outlaws, could not get on any planet. Parts, machines, all those things."

"Not all that," objected Bankill.

"It is a guess. But I think it intelligent because otherwise one of those ships would have got through."

"Perhaps the next has. We can only wait and see. And we must try to find energy where energy is not. How much chemical energy have we?"

"About the equivalent of one accumulator bank," answered Norden. "One-tenth of that is stored in the rocket ship Horensen has put at our disposal. It will all be available energy, however, because it is nearly all in the caesium metal stock. Some in rubidium, though that is practically the same, and rather unimportant. Some energy is in the concentrate of plutium. That's the same as caesium, except that it's slightly more active, slightly slightly heavier, slightly radioactive. We can use it, though, in Passamock Dome. The heat released in getting electric energy will be used also."

"The Dark God of this planet must object to our robbing him of his treasures," sighed Bankill. "We are helpless."

"Probably," agreed Norden, "but not certainly. We can still try. Men who braved the hardships of this utterly desolate world for the scanty return the rare metals yield will at least make helpful, courageous workers, if a way shows itself."

"Way! Sirius is nearly as hot as the sun is here."

"We can still try," replied Norden. "I think I will return to my lab now. I am available any time I am needed. Horensen, can I put you up?"

"Swell. That would be fine." Horensen rose to his feet, a towering giant. "Maybe I am more of a nuisance than a help here. I use a lot of air." He grinned.

* * * * *

DEAN NORDEN walked along the street silently. Horensen had returned to his ship from the Government House; he missed the Norseman now. The street was silent; silent people walked along it, thinking deeply, nodding slowly to friends.

The little, thin, metal-walled houses were silent, the laughter and voices of normal times were missing.

The usual deep throb and roar of the metal plants were gone, too. The works were shut down. They took energy. For the first time Norden heard the thin whine of the ineffably cold wind about the dome, keening mournfully the dirge of a dead planet. He looked up, He was near the edge of the dome here. The up-?ung crystal wall sparkled faintly in the heat-lights of the buildings, and a thousand shining droplets trickled down it.

It was raining outside, raining liquid nitrogen. Beyond; the wind-whipped wisps that were Pluto's rain clouds scarcely dimmed the stars that twinkled and danced in the wildly whipped air. This was a violent storm. But it wouldn't work a one-horsepower wind-generator. The atmosphere was too light.

He turned down the street, then left and went to his own home, set hard against the thermalite dome, with a private, experimental lock in its rear wall. In his laboratory he paused to look about him. There were a thousand pieces of apparatus he didn't dare use, now. field generators that took a thousand horsepower hours. Current density apparatus, that took even more.

He'd been working on nuclear bombardment, hoping to get a bombardment process

more than one hundred percent efficient. He needed it now-and the best he'd ever done was one ten-thousandth of one percent efficiency. There was the tantalizing knowledge that the infinitesimal fragment of his bombardment, that was striking true, was yielding something like ten million percent efficiency.

Atomic power. He could release it all right—when he could ring the bell with his shots. But only one in several thousand billion was doing that. And it was hopeless to try that now.

Transmutation would be more to the point. Transmutation of anything—gold, for instance, to oxygen. For, with a supply of oxygen, the free hydrogen of this atmosphere would yield them power.

Norden walked outside and studied the dim, white expanses, cleft gashes in the dead white flesh of the planet under eternal, winking stars, and a now-rising sun, tiny, light-less, heatless. The eternal mystery of space

looked out of that blank, cold sky, mocking him with the mystery of missing ships, a broken chain of supplies that should have reached Pluto. The broken chain that stretched, at intervals, across the more than three billion miles to the Minor planets, where warmth and heat were natural, not cold and desolation.

Once each two weeks, for fifteen years, the ships had come, before that once a month, bearing their thousands of tons of supplies across the infinite void. Now-the chain was broken. The power-line that led to Earth-and life. There was no escape, no help, save what they could wrest from the dead world. Power. Power that synthesized their foods, power that warmed them, power that wrested oxygen from the frozen glaciers of ice, that separated the rare elements that paid for that power. Without it there was no food, no water, no air, no heat and—no life. . . .

Chapter II

The Man Who Couldn't Sleep

SOME one hundred and four weeks before, No. 376, the Tarragoon City, took off from Earth in a wash of flame, roared out to the Moon in a leisurely way, restocked a bit, and swept on out into space. Her trip had begun. She reacted slowly, her great bellyful of fuel-mass and gigantic accumulator stacks charged. Her power accumulators were feeding intense energy to her rocket chambers that exploded the water to gas instantaneously, and rocketed her ahead.

Chief Pilot Graham Barren looked sourly out of the port, while Chief Assistant Tom Dugan prepared to turn over to him.

"She's all set, Gray—don't go to sleep on watch," Dugan said solicitously.

Graham Barren looked at him with increased acidity.

"I hope to hell I do. I'd just love to wrap that grinning mug of yours around an asteroid. I'd love that even more than going to sleep."

Dugan laughed.

"Well, I won't really worry. You're a handy sort of freak, and I wouldn't mind so much myself being that way. Why, just think of your 'meteoric rise' in the Service. Without your 'rare and interesting' affliction,

you wouldn't be half the man you are. Why, I wouldn't know you if I saw you asleep."

Gray Barren looked at his chief assistant dourly.

"I wish you'd get it, too. Or bugs in your bunk. You at least get a rest and a chance to forget where you are."

"Hmm-m-m-maybe so." But think of all the work such a man as you accomplishes in a lifetime. Why, while I waste a third of my young and useful life, you work on endlessly, always alert-always vigorous."

Gray snorted.

Dugan laughed as he swung himself, deftly toward his bunk. The ship ws still accelerating toward the sixty-mile-a-second speed she would maintain on her two-year trip to Pluto. Gray Barren settled himself in his bucket seat more comfortably, with wide-open eyes straight ahead. They were still in the Earth's gravity, still in danger from meteors deflected toward Earth by its far-flung attraction. They had to round the sun, a slight, and unimportant increase in the three billion mile trip to Pluto, and presently the sun's pull exceeded Earth's.

The speed mounted swiftly as the ship fell toward the primary. The rockets roared steadily, softly, droning a message that was a snoring lullaby to the cook, the mechanic, the engineer, and the chief assistant, after eighteen hours of steady duty. To Barren, it was simply another sound. He had been on steady-duty for thirty-two years. In all his life, Gray Barren had never slept. At three he had been a curiosity of the medical world. At four, when they had learned how to make selective stains for X-ray work, they found the secret. A very minor portion of his brain was missing. The sleep center. He never had slept. He never would sleep.

Naturally, he had drifted into the transport business, taking two men's jobs that he might find occupation always. Naturally he had been shifted to space-duty, where constant alertness is the price of safety.

To Barren there was no tiredness, no sleepiness. He made a wonderful space pilot. He rested, when he felt he could spare the time, but he never slept. He could not, and the dreary two-year run to Pluto, the dreary two-year run back, were an eternity of wakeful emptiness to him.

THE seventh day they passed the sun, at some one-hundred and forty miles a second, with all screens up, rocketing by in a

parabolic orbit that swept them out toward Pluto. Gradually they slowed under the sun's drag as day after day drifted into weeks and then months. Mars they passed coming slowly around in its orbit, Jupiter one-third of the way around the sun was ahead, and "below" in the plane of the ecliptic. They had swerved up and out of the plane to pass the asteroid belt at a safe distance.

The Minor Planets were behind now, the asteroids below, and far ahead, the domain of the Majors, the space of mighty distances.

The Minor Planets, huddling near the sun, gave way to the majestic Majors spread at enormous distances. Half a billion miles to Jupiter, it was. Their trip would be one-fifth completed, for their speed was higher here, before the drag of the sun slowed them to their base speed.

Dugan was on duty, Gray Barren sitting beside him, talking and watching with him as they swung far and high toward the orbit of Jupiter. This orbit was as unsafe as the asteroids, for chasing Jupiter round and round eternally, in the some orbit, came the

Trojan Planets, centering at sixty and one hundred and twenty degrees from Jupiter in the orbit, spread out in diminishing numbers all about. The sixty degree Trojans were near now, tiny worlds following in imitation of the giant, in his very footsteps, three years behind him.

"Funny little worlds. Are any of the other planets tailed that way?" asked Dugan speculatively.

"Probably not. Jupiter grabbed those himself from the asteroids, and no other planet could have done it."

Hm-m-grabbed 'em how? I wouldn't say he had 'em."

You know the why of the breaks in Saturn's Ring-system?" asked Barren.

"You mean why it's striped, instead of a single band? Periodic tidal influence of Saturn's major moons, isn't it?"

"Yes. The asteroids are the suns Rings, Jupiter his major moon. The asteroids occur in three main belts, and several minor

ones. An asteroid that revolved in exactly one-third of the time Jupiter did would get three kicks a year from Jupiter's pull. In

exactly hall the time, two kicks, two-thirds the time; two kicks every three years. That makes bands where no orbit is stable, and so there aren't any planetoids.

"These Trojan planets were once in unstable orbits perhaps seven-eighths, and finally got kicked hard enough so that they

were forced into an orbit that was stable-here in Jupiter's own, where he has no in?uence on them. The Major Planets helped,

of course, to make it stable here by their influence on them, and Jupiter still ruled them a bit, so they fell into the sixty and one hundred and twenty positions."

Dugan scratched his head.

"Couldn't Saturn collect some that way, too?"

"Jupiter would grab thein and pull them back on the way out. If they went beyond Jupiter, Jupiter's pull would tend to pull them back. Inside, his tidal action pulls them out."

"Hm-m. Too bad Earth hasn't some. They'd make handy starting stations for Pluto—wouldn't have to-duck—down—"

Dugan sounded like a phonograph running down. Gray Barren started up instantly, staring at him. Dugan, wide awake, new

on his shift, had fallen asleep in the space between three words!

"Mac!" roared Barren. Simultaneously, as he called for his engineer, he pulled Dugan out of the seat, and slid into his place. "Mac—come here. Dugan's passed out!"

And then Barren listened. There was not a sound in the ship. It seemed a ship of the dead, until suddenly a soft ripping sound

from behind made his face tense even more. That was the utterly unique "cloth-saw" snore of MacMurdy, the engineer! And

Mac had just come on shift, too!

BARREN reached over to Dugan suddenly, pulling him easily across the floor of the nearly weightless ship. He shook him until his head seemed about to snapoff his neck. He slapped him vigorously, then listened tensely for his heartbeat. His heart was beating strongly, with the deep, regular, easy beat of a sleeping man.

Gray Barren looked at the man sourly.

"Methinks something's all-fired wrong," he muttered. He looked out of the great thermalite port, and swung the ship on its

gyros through a complete circle, so it was traveling backward, and he could see what had been behind him.

There was nothing whatsoever to be seen outside. Gray snified deeply, testing the air wiith his nostrils. "There was no unfamiliar odor.

And then he noticed the radio-frequency ozonizer. It was shooting a soundless discharge four feet long into the room, washing its insulated pedestal with an eerie, blue light that was quite unfamiliar.

Barren reached for a tumbler instantly-and even more rapidly snapped his arm back as a snapping discharge ran up his

arm, almost paralyzing it.

"And that proves my contention," he said aloud. "It isn't in the ship, by Pluto!" Again he swung the ship about its gyros, avoiding the ozonizer tumbler. The flame discharge died momentarily "as the ship swung, to increase again as it pointed head on once more. Barren swung the ship back, very slowly, until the flame reached a minimum. He noted the gyro settings, and swung the ship the other way. One hundred and eighty degrees away, the flame reached another, equal minimum. At ninety degrees it reached a maximum. Barren set it on the maximum, and looked dead ahead. Only blank space showed, and the unwinking stars of space, and the tiny Trojan Planets.

Then he saw it! A moving dot of light down there! Another ship in space! And at the same moment, weight, a faint acceleration not produced by rockets, came.

As quick as thought, Barren's hand darted to the rocket control. The shi leaped straight forward with a roar of the emergency rocket drive. Ten Earth gravities slapped Barren flat in his seat, consciousness nearly gone. Abruptly, the acceleration of

the ship dropped, yet the rockets thundered on, loud and harsh!

Again his hand streaked out, as it was released of the crushing weight by the interfering force. His face went white and tense, and behind the set lines of his lips, his mind was working at lightning speed.

"Jupiter it is, by the Gods of space! Jupiter, with two and a half Earth gravities as normal. Speed is nothing, nor acceleration!"

His hands moved again, with a slower, surer motion. The ship pitched and tossed, rocked to the drive arid counter-drive of emergency flaming rockets. He was shaken in his seat, back and forth, while the strange counterforce again and again partially neutralized his accelerations.

Still he persisted, working with a grim, slow determination. His mind calculated constantly, thinking with untiring, swift precision, while the carefully used acceleration thrust the ship first one way, and then another. Each blast sent him slightly ahead; slowly his speed was stepping up.

It was hard work. Only a freak could have done it.

Chapter III

The Sleep Ray

DUGAN woke to a ship that was quiet. Every trace of rocket rumble was gone. He was lying on a temporary bunk in the control room, held down by the rubber restraining sheet that made it possible to lie in a bunk in a weightless ship. Immediately

he became aware of two things. Barren was standing over him with a hypodermic needle in one and, a small tube in the other.

Dugan was very sorry he had awakened. He ached from head to foot, as though from a terrible beating. His left arm, he realized, was very, very painful, and seemed peculiarly stiff. He groaned, and looked at it. It was neatly splinted and bandaged.

"Who got mad at me?" he asked, looking out through his left eye at Barren. He realized it wasn't a very good eye, but the

right was worse, and sorer.

"I don't know exactly," replied Barren. "I conldn't catch the name, but that's all right. He didn't catch us. But I think it

was either Priam or Hector. Anyway; he came from the Trojan Planets at sixty, fought like a hero, and held on like grim

death. He's probably a hell of a good scout when you know him, but I don't want to, so I left."

"Where's Mac?"

"Not so lucky," said Barren grimly. "Trailing along behind about half a mile off. He's got company, though. Brady and John

are both with him."

"Dead?" gasped Dugan softly. "What—"

"I stopped to wedge you down between the pilot seat and the wall with my feet after you had taken only a few tumbles. I couldn't leave to strap them down, and, anyway, I think Mac socked his head on the rocket-tubehead on the first jump. It's rather messy back there. John was working in the galley, and a cleaver fell off on him under ten g's. It flopped around back there with assorted pans and cutlery for nearly seventy-two hours. It took me several hours to get used to that place. Brady was in the rear end of the ship, got wedged pretty quickly, evidently. So I dropped 'em all out in space."

Dugan looked at him for a minute, and his face went white, then greenish; When he was through being sick he lay back weakly.

"What in God's name was it?"

"A ship from the Trojan Planets." His voice became professorial, reflective. "I've always held that a paralysis ray was impossible because if it acted on muscles it would paralyze the heart, which is another muscle just like the voluntary muscles, and if it acted on nerves it couldn't find any distinction for the voluntary and involuntary muscles. My error. The gentleman back there had a beautiful solution; It acted on the sleep-center of the brain.

"Unfortunately, I haven't one. I'm a permanent insomniac, and even the sleep-ray apparently offers no hope. You went out like a light in the space of three words, never knowing what hit you. I didn't either, because I wasn't affected at all. I found out, though.

"Somebody wanted our ship. I got kind of worried toward the end, because we haven't enough fuel left now to slow for a proper landing at Pluto. We have an excellent chance Of seeing Alpha Centauri at close hand if we don't hit right. Plenty of energy, but no water to throw off."

"You burned all the water?" gasped Dugan. "There was water enough to stop us one and a half times."

"I used emergency acceleration for nearly seventy-five hours running."

"God, man, you're' not human. No human-being could stand that for seventy-five hours!"

"That's what I figured. So did Hector. He stopped hectoring me after a while."

But,what happened-what was it?"

"A ship from the Trojan Planets. He had a tractor beam of some sort, with a pull like a ten-inch steel hawser. And a sleep ray. He put you out, and I began acting up. Evidently he figured everybody was out cold, the way he was approaching a strange ship, so I tried running. He slapped that beam on me, and came at me so fast I couldn't believe it. Then I remembered be must have come from old Jup originally, and been used to real accelerations. Evidently he was. My ten g's didn't phase him.

"He pulled up to about a hundred miles of me, and looked me over while I was cavorting. I decided the only hope was to make him think the mechanism had gone wrong, so I played it for all it was worth. And he played the fish at the end of the line for all it was worth. He wanted this ship. I'll bet he wanted the energy we're carrying, and about that time I wondered if it was such a strange ship.

"Right now I wonder if there are any other ships like this between here and Pluto. Maybe Hector's been making a collection.

If so, they'll all be dead out beyond there, from cold and lack of power. The last news we got from them, remember, was two

years old. Hector may have been at work for three years or so, now. In which case it won't matter if we miss Pluto.

"Anyway, I kept trying to shake loose for seventy hours or so and Hector must have been getting tired by that time. He, too, must have figure no man could stand it that long; it must be crazy machinery. And then came a little blessing. A nice meteor, making about forty miles a second toward a rendezvous with the sun, and going about one hundred miles per with respect to us. I spotted it on the detectors, and started some tricky angling. We're shy the last ten feet of the ship, by the way.

"That seemed to convince Hector, and I turned a bit Of power loose in the leads back there. We've got an awful lot of power on board and I thought it was a good cause. Evidently some of the leads were shorted, as I had hoped. Anyway, the whole rear

end started shining. I turned on the rockets for straight acceleration at two gravities and made it wobble. Hector let me go. Most remarkably persistent cuss, though.

I had to rest for several hours after that before I set about cleaning up. Your arm ought to be about healed. You've been out

a heck of a time. I thought it might be a good idea to start you going again. Those bruises you collected are almost healed now.

You should have seen yourself about ten days ago.

Great God, man. Attacked in space-is there some pirate race in this System? One we've never suspected?

"I know it. Hector didn't seem the friendly kind. Maybe he didn't want to be suspected, and we never did poke into Jupiter

far, you know. Whatever Hector's made of, it's tough stuff, to live on that place.

"All our fuel's gone. There's no way to warn Earth. Pluto is probably dead. And two weeks behind us those other fellows

are following blindly into that trap!"

BARREN looked at his companion with a hard eye.

You think that I haven't thought of that? Haven't been thinking of it for days, while you slept, thinking of it twenty-four hours every day? There isn't one blessed thing we can do. Radio doesn't work here, where there's no Heaviside Layer to protect it from the sun's radiations. Searchlights can't carry the distance from here to the next ship. We can't turn back, for two reasons.

"They may, however, have started that collection only recently, and the devils out there on Pluto may be dying for lack of

power, the billions of kilowatt hours we carry. I figured that, with no machinery running, they could heat three domes for nearly a year on the power we carry, and feed their people and heat the place for three months—if we had all our power. As it is, we carry two months life for them, if we land intact."

"Yeah—but how can we, with nothing to discharge, nothing to repel us?"

"We have something to discharge. Not a lot, about enough to slow-us by fifteen miles a second. Sun-drag and all will leave

us only about twenty miles a second, then. But I'm not going to use it that way. Pluto has some air, and it's awfully cold air. I think we may be able to use that for a brake; if we have some maneuvering power."

"What! Brake a ship—air-brake it? From twenty miles a second?"

"No, from thirty. We won't use that fifteen miles a second fuel. We'll need some thing else than braking-we need maneuverability."

"It's impossible," said Dugan wearily, settling back.

"But we may as well try. It'll take us nearly eighteen months now. That's a lot of time to figure."

Dugan only stared at him.

Chapter IV

Emergency Landing

THEY had time to figure. Gray Barren a twenty-four hours a day for eighteen months, and Dugan had eighteen a day for an equal time. First they checked the ship very thoroughly, then they calculated stresses, accelerations, a thousand things. They calculated and discussed very leisurely for six months, with lots of time and nothing to do in the end—but die. And then they rigged up some weird apparatus.

They put a large bathtub, big enough for the two of them, squarely in front of the control board. Then they insulated the controls extraordinarily, after three months of work and thought; so that they wouldn't get any back-kick from the electric circuits, while trying to control. And they rigged up pulley-controls, so they could control while lying flat in water; the little water left.

Then they sawed free the broken beryllium plates from the tail of the ship; where the meteor had slapped it, and spot-welded them-on very securely as huge fins. They added control surfaces, which made the whole ship look like some madman's dream of an airplane, with fifty stubby wings at wrong angles.

The wings, they hoped, would hold the ship, the crazy, broken ship, in a cockeyed parabola around Pluto, and through Pluto's atmosphere, when it reached that planet.

They had lots of time. And they had space suits to work in, so they worked slowly, calculating much, and they didn't know

the viscosity of Pluto's upper atmosphere because nobody had ever thought to measure it, and they didn't know the aerodynamic resistance of that smashed tail, because nobody had ever expected to measure a thing as crazy as that. And, of course, they didn't have fuel enough to make any real corrections, and still land in one piece.

Gray Barren made some wonderful and fearful extrapolations. He calculated that their crazy ark would ride the thin, cold air of Pluto at an elevation of 15 miles, and at a speed of half a mile a second, on the wings.

Tom Dugan laughed.

"If this rolling-pin will float in anything less dense than mercury at less speed than ten miles a second, I'll drink it."

"You can make a parchute, and jump out, if you wish," suggested Barren.

"In that air? Parachute descent on Earth—sixteen feet a second. With a half-acre parachute on Pluto you drop forty a second.

I'll stick to this old space-hog."

"Hm-m-m—it's highly probable you'll stick-so tight they'll scrape you up with putty knives," agreed Barren. "We can but try, though. I'd rather go out in a nice blaze of glory than starve to death en route to the Lesser Magellanic Cloud."

"Maybe the guy you land on, on Pluto, wouldn't," ventured Dugan. "What shall we aim for? That's one thing we haven't decided."

Barren stared at him in mock distaste.

"Those finicky people! We'll aim for Pluto, of course. If we hit it at all; we're damned good. If we happen to hit a city, there's nothing I can do about it. But, remember, the cities don't really cover much territory on the planet."

"They might not welcome us very heartily if we landed on Tarragoon. That's the only power source on the planet, which same must he the dearly beloved darling of the people right now."

"If we land this can successfully, we will be darlings, too. Go on to bed, you lazy hound. You've been rubbing your eyes in a disgusting fashion for two hours. I keep forgetting you have to sleep."

BARREN and Dugan had programmed their work well. It was finished a month out from Pluto, and for a month they had nothing to do but recheck calculations and the crazy patchwork they'd slapped on the outside of the hull. Meanwhile, slowly, slowly Pluto enlarged in the void ahead.

FOUR hours previous to the test, Gray Barren lay down and rested. Dugan slept the clock around in preparation. They were approaching Pluto at thirty-one point seven miles a second. Months of work had prepared elaborate charts and tables for every conceivable speed and angle.

When Dugan woke up Barren was already at the controls; carefully checking tiny bursts of the precious rockets, directing them more accurately at the exact angle he wanted. Pluto was a dim, white giant in utter darkness ahead. Already tiny light flecks indicated well-known places. Tarragoon shone dimly, as did Ranatook and Passamock. And, at the point of a triangle from Tarragoon and Ranatook, they saw a new spot. Dugan looked at it silently.

"They aren't dead yet; thank God," he said at length.

"I wonder how many-ships got nabbed before us," mused Barren. "These may be the last living people down there. They would stay in Passamock and Tarragoon—the biggest cities. Ranatook and that new one I don't understand. Caesmatite City is dark, so are some of the others."

"There are some, anyway."

"Yeah. This is Saturday night. Get ready for your bath."

Dugan stripped off his uniform, ending with a tight-fitting elastic undersuit. He settled himself beside Barren, who was already prepared.

I hope you heated that water," Dugan grunted.

"I did," replied Barren. He turned the faucet. "Look out, here it comes."

The ship accelerated gently under a droning rocket gush, and suddenly a four-inch pipe spouted water into the "bathtub." Both

gasped simultaneously. Barren hadn't exactly heated the water. It was ice-cold. He shut of the stream, shivering.

"Hell if your calculations are all that bad, I'm going to walk home." sputtered Dugan. "Turn on some heat." Dripping, he got out of the pool of icy water hurridly and stood before the big heater, shaking. Barren was busy. Presently he turned the water on again, and yelped. Now it was a bit too warm.

"Why didn't we put a bath thermometer in here?" growled Barren. "Come on, Tom, it's getting right now."

Presently their flotation tank was three-quarters full, and Barren relinquished the controls to Dugan while he put on the oxygen mask he had prepared. Then he took over while Dugan did the same.

"Our periscope thing is fairly decent, at that," commented Dugan, looking up to the mirror that reflected the scene outside the pilot window. Pluto was growing rapidly, with terrifying speed. The instruments on the control bank registered clearly in a second mirror.

"Hm—m. But we've got work to do. Look out!" The ship lurched slightly, and the water and men rolled to one side of the tub.

Dugan grunted.

"If you hit any air pockets you're apt to find yourself swimming along the ceiling, and drowning the instrument board."

"That would be tough," agreed Barren. "Any suggestions?" He worked busily for a moment. "Were headed right. We're going to smack that air like a solid wall, though. Take a deep breath and count—"

They hit the air. The fringes of Pluto's faint, thin air. Instantly the ship screamed, her whole 200,000 ton mass shrieking in violent protest, and the men sank like leaden

masses through the water, water that crushed suddenly on their chests.

HALF conscious, Barren saw a faint glow appearing in the outer wall. The ship was almost red-hot! Then, in an instant, the acceleration was gone. The ship creaked in every giant strut as she resumed equilibrium, and the two men floated upward like corks.

"The gravitometer's broken," said Barren painfully. "And that was just the first shock. The seventh is the worst!" In the mirror Dugan, could see the gravitorneter needle twisted around the "Stop" pin at twenty-two gravities.

"The flotation method saved us," he said at length. "Normally, the gravity would have made us grease spots without the water. I must have weighed two and a half tons. God—what's the seventh going to be like? You said we'd get only twenty gravities that time!"

"Huh-I said we'd be going thirty-one miles a second, too. My error. Look out, we're turning." The ship pivoted around, twisted, then the rockets droned emergency acceleration as the ship swung back in a vast circle, to dive through the atmosphere again. The rockets were not being used to stop the ship, only to de?ect her, and Pluto was helping, had helped already.

But it was a day later when they dived into the planet's air again, to be loaded now with nearly three tons of weight, while the ship's weight became nearly six million tons. Only the hundreds of small fins, distributed over all the ship, and the utterly frigid air, thin as the average man-made "perfect vacuum," made it possible.

But the speed dropped under that harsh treatment; It dropped so they turned back in three-quarters of a day this time, and a third of a day the third time. And each time they underwent the terrific stress of those loads, each one greater than the last. But they were learning, becoming accustomed to impossible accelerations.

And—the ship was shedding fins like a bird under a cat's claws. It was shedding fins, and plates, and even great structural members, members that shrieked like meteors through Pluto's thin air, alarming and warning the millions on the planet.

ON PLUTO, five million eyes were watching that mad ship, watching with hearts in throats. Something was wrong, horribly, horribly wrong. But whatever this mad messenger might mean, it had meaning, it had information. As each shattered fin screamed to the planet, the people groaned. Each time as it shot, unchecked, out into space again, they groaned. Each time it returned, mad rockets flaming, they groaned.

And in it Barren and Dugan groaned under the load. At last the fatal seventh trip came—and passed. Behind them, a third of

the fins lay broken, wrested free. But Barren sighed in relief.

"She's under what you might call control, now, if the rest of the fins stick on. I'd like to plaster on a few more, but I can't now. We'll hit again in half an hour, I guess, and I have to hold her in this time, if I'm going to land without wrecking it. I've just about enough rockets. I'd like to make Desolation

Plain."

"You've eight miles a second to handle; orbital speed is five," said Dugan.

"Yeah—but at this speed, even with the fins I have left, I have a hell of a lot of lift to hold me down and brake with. Most of

the fins that tore of seemed to have been brake-fins rather than lift-fins. They got more strain. Here, take this pump lead, and

when I say 'dump,' you pull that. That'll let the water out. If you don't, we'll have that control board swimming, and be minus

control altogether."

"This bathtub would be inconvenient in the switchboard," nodded Dugan. "I never did like taking baths, but this has been the

queerest bath I ever took. I'll be glad to get out of it."

Air shrieked outside. The ship heeled again, the great members groaning under terrific loads. Abruptly the rending cry of torn metal echoed, the pop of exploding rivets and broken welds, the long-drawn howl of stretching members. That didn't bother them any more. They were used to that. They labored in the water, their breathing a terrible torture. Barren's face was white and set with intense concentration and pain.

"Damn—lift—fin. I'm—afraid we're—slipping," he labored. An unusually loud shriek of parting metal was followed by an abrupt

smack and thud throughout the ship, then a sudden increase in weight. Barren moved instantly, laboriously. The weight decreased, and a tortured smile appeared. "Main-member thirty—seven. five of the brake—fins. Lots-of-lift."

The ship howled and shuddered, and the thin, cold air shrieked in torment for half an hour. But the ship was completely under control. Twelve, times they circled the planet, biting deeper and deeper into the air, before Barren called, "Dump," and the water sucked out of the flotation tank.

The ship was slowing far more swiftly now. Gray Barren was looking at his charts and tables, calculating swiftly, mentally.

"We're just about going to make Desolation Plain. Near Tarragoon. Be there in a minute."

DUGAN made no answer. Barren looked at him and grinned.

"The lazy dog-he's gone to sleep!"

Dugan woke, heavy-eyed, his mouth thick, and tasting like the inside of an old shoe, wakened by the silence.

Barren was rising, stretching, ruhbing incredibly stiff muscles. He looked down at Diigan. "Hello. You are a help. We're here!"

"You landed this impossible can?"

"Well, it isn't falling any more, and it seems to be standing still. I took a look back-side. The skin's gone halfway, which

must have been a big help; it certainly increased air resistance. Landing wasn't bad. I even have three-quarters of a ton of water left."

Dugan snorted. "Three-quarters of a ton! One gravity for Seven-hundred seconds!"

"There's a procession of some kind coming out from Tarragoon. They're comin' hell for leather, too. I used the telescope,

and it looked like old Horensen was riding in the first one with Doc Norden."

"Old Horensen! The old boy would get through. I wonder if Hector tangled with him at all?"

"Don't know. But I hope they get here soon. The air tanks went out with that thirty-seven member, and we haven't any air left. I guess they will, though."

Chapter V

Norden's Experiments

BARREN looked into Pilot-Commander Horensen's eyes and smiled.

"And," he finished "it wasn't much of a trick to land after that. But do you mind

my saying that I think the driver of this snow-car is either a homicidal maniac or has no respect for his neck? I worked awfully hard for mine, and I wish he'd either stay at least six inches from the edge of that canyon, or drive slower than seventy miles an hour."

Horensezi chuckled deep in, his throat.

"Don't tell me you're nervous. I saw you land your ship. You were scattering mainframe members all over Pluto. I didn't think there would be so much left."

"The main question, still unsettled," broke in Norden, "is the amount of energy you have left."

"Main accumulator banks one through twenty-seven are untouched," Barren answered. "We drained twenty-nine and thirty, and twenty-eight is about three quarters gone. In other words, about ninety percent delivery left. The same applies to the machinery we were delivering, That was pretty well tied down, and only a few things seem to have broken loose. We have some junk for you, I think."

Norden shrugged his head. "I wonder what it would be. Oh-I know. And, by Pluto, I can use it, if it's what I think. Hard to remember—I ordered it four years and more ago."

"I hope it's what you want, then. Because I rather think you won't be getting any more shipments for another four years or so—if at all. What I hate to think of,"

complained Barren, "is that flock Of good guys I know who are plowing blindly into

that damned trap one after another. I have an uncomfortable feeling Hector's pals won't know the difference between the larder and the passengers any better than they know the difference between 'meum' and 'teum'."

Horensen growled deep in! his throat arid looked away. "Barney O'Malley was following you." he stated gutturally.

"He isn't any more," replied Barren concisely. "We were better than twenty miles under speed for the last two months. He would have passed us."

"I think I must learn how to be without sleep," said Horensen. "You've got to now to survive in space."

"If," said Norden practically, "we started a ship back now, it would get there in two

years. In three years enough of a fleet could be started to do a little investigating. In four years a supply fleet could have been started out toward us, perhaps. That makes six years before effective help could reach us.

We aren't a bit better off—because our supplies can't last even one-twelfth that time. I don't think you saved your neck to much purpose, Gray."

"Well, maybe not, but anyway I'll have someone to bury me here. I hate floating in space. Mac and Brady and John followed us in sight for six weeks, and I don't like floating like that forever."

The white of the air prop and the soft scrunch of the snow under ski-caterpillar treads were the only sounds for long minutes. Tarragoon Falls was a bare cliff, now. There were no Falls to the left of the winding trail; all the power was being used.

"We haven't made any progress," sighed Norden. Slowly grim determination came into his face. "Gray, where did you study?"

Gray Barren looked at him speculatively.

"I majored in physics at Cal Tech. But I'm a rotten mathematician. I got hooked

into Transport and shifted to Interplanetary because I didn't sleep. I've kept up on the Journal pretty steadily, except those four-year blanks I hit taking these trips, but you can do a lot of studying when you're alone on watch in space, and never sleep."

"I thought you took physics," said Norden quietly. "There isn't a ghost of a show for us Devil's here, and I guess you're a Devil perforce for the duration of the emergency' as they used to say, in any known thing. Do you reason the way I do?"

"I did an awful lot of reasoning in eighteen months, Dean. I started thinking about this about sixteen months before you did, and while I had a few other things to worry about. I sort of reached some conclusions, too. I don't want to be discouraging, exactly, but old Pluto can support about one—no, three-thousand people, now. And there were two and a third millions here, the last

I knew."

"And a half, now," said Norden. "Life follows its usual course, even here, displays its characteristic of multiplication."

"Well, there's nothing known that'll help you. That leaves a lot, though.

Dean Norderi answered sourly.

"Yes. The strange things we don't know about. They're lots bigger than the known, but harder to use, I fear."

"Oh, well," grinned Barren, "necessity always was fruitful?"

GRAY BARREN'S and Tom Dugan's luggage had already been transported to Norden's house when they returned from the Government House. Norden looked tired and drawn. Dugan immediately went to bed. Gray looked at Norden quizzically.

"Ah, there, lazy-bones. Run along to bed. I want to rest a bit myself. I suppose you sat up and watched us cavorting overhead."

Norden smiled.

"All Pluto did for the last four days. They knew you were probably bringing power-and news. The people silently hoped the power chain had reknit."

"Go on and sleep," ordered Barren. "I'm appropriating this couch here."

Norden followed Dugan into retirement while Barren made himself comfortable on the couch. - Half an hour later the musical moans and snorts from Norden's room amused and disturbed him, and he raised his lank form from the couch and started rummaging slowly through the house. Presently he found Norden's library, and ran through it rapidly. The newest books were two years old; he had newer ones on the ship, and he'd read all these. There were no new reports.

He walked slowly about, out into the laboratory, snooping, looking, trying. Presently he found Norden's note-cabinet, and started in on it. The sounds from outside disturbed him, the unfamiliar sounds of life after two years of eternal silence. The people were noisy tonight, noisier than they had been for weeks, noisy over the landing of the ship from Earth.

Barren turned back to the file cabinet, skip-reading through pages and pages of notes, analyses; test runs. He grunted softly.

"This bird Norden man, must work day and night to turn out all that stuff. He must have analyzed for every prospector on the planet. The census takers could save a lot of work just using this file. But he doesn't seem to have done—ah, there it is! Good Lord, how did that man get time for all this?"

Barren had found Norderfs private, enperimental-file. It consisted of two drawers full of carefully typed sheets of experimental data, largely characterized by an ending, "N.G., damn." Gray smiled. He took out both drawers and went back, seating himself comfortably on the couch. Presently he whistled, rose, and returned with two more drawers filled with pages of calculations.

Barren's respect for Norden grew by leaps and bounds, as be vainly tried to follow the analyses and derivations the man had run off. He got along, fairly well with integrals and differentials, recognized; matrix processes, and tensors well enough to follow, though he'd never been able to lead, but he finally ran up against something that stranded him hopelessly. It was a seven- teen-page solution of an equation of the order of x⁹. He looked at the solution, and tested the values by substitution with interest. It rather surprised him to see that they fitted.

Then Barren tried again to follow the calculations. Halt an hour later he gave up in despair.

"For the life of me, I can't figure out what he's doing," he muttered, "or what he's doing it to."

A CHUCKLE startled him. Norden was up. again, looking at the sheets Barren had just laid down.

"Solution of that noventic in Group Theory? You're not alone in that. I didn't know what I was doing or what I was doing it to, either."

"Well, it's all beyond me," sighed Barren. "What sort of stuff do you eat for breakfast here?"

Norden's face became grimmer. "We eat as little as we can live on, and we don't cook it. That takes power unnecessarily. Mostly synthite foods, anyway."

Barren laughed good-naturedly.

"That's no change for me. I've been at it for two years. But I still find it a useful habit. Let's go."

"I think I'll try that, too," came Dugan's heavy voice. "Have a nice nap, Gray?" he asked chuckling.

"No, wise guy, while you lazed away the hours, I, with my eternal, springing energy, tried to follow this man's math. He has a trick he calls mathemaiics. He does something he doesn't know what to something he doesn't know what, mathematically. The only trouble is, he gets the right answer. I still don't believe him, but he's got the answer to an equation he certainly couldn't get any other way."

Dugan grinned.

"Well, my stomach is shouting an equation to me-and I'd like to solve it!" he said. "Let's eat!"

The food was simple enough, artificially flavored solids, artificially compacted jelly-like proteins held in a mesh-work of woven threads of digestible carbohydrates. Their artificiality was blatant, but they filled lean stomachs, and supplied vital energy in almost totally digestible form. For drinking they had a slightly stimulating, clear-colored liquid, flavored with citric acid, synthetic orange oil and sweetened with glucose.

Chapter VI

Power for Pluto

BARREN seemed thoughtful as he ate. finally he spoke.

"I raided your files, Dean, and-by the way, I don't see how you got time to do all that analysis work and experiments, too."

Norden laughed.

"I fool 'em. Did you notice that battery of spectroscopes? Most of the analysts here go after the stuff chemically. I put a hunk in an arc, and get a complete analysis record in an hour."

"You can't read a spectrogram that fast."

"No—which is why the others don't use that method. I have one of those spectroanalyzers."

Barren whistled.

"I didn't know you had that much wealth, Norden. You're a bloated plutocrat, as they used to say. Those things cost about twenty thousand dollars, don't they?"

Norden nodded.

"I sank every penny I could gather in that machine," he answered. "Bought it back on Earth before I came out. It has paid me well, because the men like my quick analyses. For a while they questioned my accuracy, but I offered the sum of one thousand dollars to any one that found my analyses wrong."

"I thought you had put all you had in that gadget," Barren said, puzzled. "How would you have paid up?"

Norden smiled.

"I never make mistakes. They never found out I was broke."

Gray Barren smiled in admiration.

"To get back to your notes," he said, "I see you have been playing around with atomic structure, and evidently, from some of your matrix mechanics there, thinking of atomic energy."

"Yes-condensation of hydrogen to heavier elements. Helium particularly. This world has more hydrogen than needed to balance the oxygen, and no energy. Atomic energy is our only chance."

Barren nodded. "Yes. That would be very convenient. Solve all our problems. But the most practical stunt would be to use the energy already freed by the sun. We'd have to perfect a solar energy collector."

Norden snorted.

"Where are you going to do that—on Mercury? It is a bit dilute out this way, you know. I don't really see how you could."

"I've been playing with that problem for the last eighteen months," continued Barren. "Do you know how much energy is available here? It's dilute, all right. But-Pluto has a good bit of collecting surface."

Heat-energy you mean? I never stopped to calculate the exact power Pluto does absorb from the sun, because that energy is at such a low level of availability. It's only about seventy degrees above absolute zero."

"Not very hot. But there's more heat in a ton of liquid air than in an ounce of liquid steel. And there's an awful lot of tonnage here."

NORDEN shrugged.

"You've got a sort of worm's-eye view of heat, though," he said. "You would have to crawl down awfully low to have that heat fall down on you very effectively. To get the energy loose, you'd have to work from an even lower temperature, and, God knows, this place has low temperatures to start with."

"There's still about one hundred and fifty billion horsepower available, though," Barren persisted.

"That's not a heck of a lot, even so. But do you really think heat energy is the best bet? That's actually the energy received from the sun constantly. But how much sun power does this planet receive?"

"Astronomically speaking, it's a drop in the bucket, but astronomical drops in astronomical buckets are so terrifically big," Barren pointed out.

Norden shrugged his head negatively.

"I'm afraid it's even more hopeless than atomic energy. At least the sun does use atomic energy, but nothing can use heat energy of such low availability at this which we have."

"My good man, your reasoning is cock-eyed," Barren snapped. "What's heating this city now?" he asked.

"Tarragoon Falls. You're right, by Pluto! That is an indirect means of making heat energy available. The vapor is lifted and carried by heat, isn't it?"

Yes, I thought so. But we need something better than that. Look here, when you put an atom in a powerful magnetic field, the electrons rotating about the nucleus act like current-conveying wires in a coil. They're susceptible to action by a magnetic field. If they are lined up righl, you can make the electrons move out by the impressed magnetic field; or, if they are going the other way, they move in. Right?

So they told me in school," replied Norden.

"Well, you're lifting the electrons out in their orbits. That takes energy—heat energy, for instance. Now, if you could make them do that violently enough you might get a real heat absorber. Then, when the magnetic field was released, they'd collapse to normal, and release energy they absorbed-but at a higher potential."

Norden laughed.

"I give up," he said. "Let's go play with your idea."

HORENSEN walked into the laboratory slowly, a few weeks later. "I just came from Government House. That makes three ships that haven't come after yours, Gray," he reported.

Barren looked up from his work with a savage face.

"I know it," he said grimly, his eyes blazing. "And Earth is probably sending those fellows out there—out to that death trap. Three months of it now. For three months Hector's pals have been sniping off those ships like one-two-three, with never a chance for them to fight back, and never a chance for us out here to live."

"Have you learned anything? Any chance of discovering some new type of energy?" Horensen said hopefully.

"Yes. We've learned seven hundred and ninety-three new, blind alleys in mathematics. We've learned seven hundred and ninety-four new, useless experiments in physics. We're even about ready to try some of Norden's craziest mathematical madness. And we've used power enough to feed ten men doing it. That is the worst."

Horensen shook his big head slowly.

"Don't get mad, Gray. That won't do any good. That power isn't wasted. It all comes out as heat, anyway, doesn't it?"

Barren pushed back his hair with one hand, and his taut face relaxed.

"Attaboy, squarehead. I wish I could sleep once in a while, just so I could forget it. Remember that I have been working at this for nine weeks, steadily, never a minute off for my mind. Norden's done all the math, of course, the real things. I'm just the help, but he does get sleep. And I haven't your calmness. You Norsemen must pick it up out of the ice you are born on."

Horensen's face broke into a slow smile.

"I hope you win out, Gray," he said as he left the room.

Barren waved good-by, turned. back to his work. He was trying to get spectrograms of hydrogen atoms in peculiar magnetic fields, and the usual multiple difficulties beset him. Half an hour's trying convinced him, and he decided to try a stroboscopic effect. Two hour's work got a slotted disc on a motor arranged in front of his spectroscope slit. Two seconds' operation heaved the slotted disc in fragments all over the room. The slots weakened it so it wouldn't hold together at the speeds he needed.

Then he tried, putting an interrupter in a gas discharge, so that the gas discharge itself was stroboscopic. It took two hours to get a plate, develop it, and run an analysis on it. he analyzer, instead of giving him, as it should, a series of spectrum-line numbers with a wavy line representing line intensity, turned out a motion picture film of a counter in action, with a gray haze overcasting the scene. The discharge in the tube built up so slowly that the magnetic field simply shifted it progressively across the field, changing its character slowly and uniformly.

WHEN Norden returned, Barren was patiently trying the analyzer; on a final result. He'd got a clean plate finally. By scurrying all; over Tarragoon, he'd found a polarimeter in the synthite food mills, borrowed it, and by rotating the polarizer head on a motor, had gotten a fairly decent stroboscope-and lost half the data he wanted because the light was polarized. That was half the problem, anyway.

Norden looked at the results silently for a moment.

"Interesting, but unimportant, I fear," he announced.

"You're right, Dean," agreed Barren. "But it took me three days to find that out, though. Well, I'll know how to do it next time, anyway. What do we do next?"

"I think I'll Just go completely nuts." replied Norden, "and set up that apparatus on trying the hydrogen atom expansion."

Barren looked at him. "You'll blow your fool head off if it works. Though I think you're still a pretty good risk."

"I'm going to work outside the Dome, anyway," Norden said. "It won't do any damage out there."

Barren laughed. "There was a fellow at Cal Tech, Smitty Andrews, working on perchlorates. Somebody in the analytical department asked him what the solubility of lead perchlorate in methyl alcohol was, and the fool decided to try it out for them. He sort of felt it might explode, so he took his mess out in the courtyard, where it could blow up in the open air.

"He knew his chemistry. It did. It broke every window facing on that courtyard. About a hundred and fifty of us got down there in a hurry to take the remains over to the infirmary or the morgue, as indicated. But Smitty was sitting on a rock, working like fury on his slide rule."

"I take it you mean I ought to go a long way off," laughed Norden.

"Or use your head and leave it alone," Barren said coldly. "Smitty knew pretty well the stuff would blow up, and if it was that explosive, what good would it do the analytical department to know it anyway? They couldn't use it?"

Norden ignored the ominous warning.

"You'll help me set up the apparatus, won't you?" he asked blithely.

Chapter VII

Norden's Machine

THOUGHTFULLY, Barren surveyed Norden's machine, days later. Pilot Commander Horensen, on a chair in the corner, eyed them curiously.

"I wish you'd give up this crazy search for a new power, Dean," Barren pleaded. "I hate picking up the scattered fragments of men. And got all of that I wanted on the way out here, after Hector got through with us."

"I'll bet this machine won't blow up," said Norden grimly.

Barren laughed, bent over a lathe.

"Ha—are you telling me? You're betting your-uh-anatomy on it. I'll bet it won't, too. It probably won't do one blasted thing. You can check that math of yours all you want to, but inasmuch as youfre the one who did it in the first place, and there's no one else on the planet that can follow it, that doesn't mean a thing. I've checked my own work too many times to think a man's own check means anything. That's why we have assistant navigators.

"Personally I, th—whoa! Hey—come, and take it, Dean!"

Barren left his machine in a hurry, running for an extinguisher and Dean Norden dropped what he was doing and ran. The slender magnesium bar Gray Barren had been machining was burning, burning with the intense brilliant flame of magnesium metal. Horensen moved with an agility unsuspected from his seat in the corner, bringing into play a liquid carbon dioxide extinguisher. He had it playing on the thing in an instant, filling the area with the CO₂.

,"Out of the way, squarehead," called Barren cheerfully, staggering up with a massive cylinder of argon. "It takes he-man stuff to put that out." He set the tank down with a thunk, and opened the valve. Instantly the gas roared out, gushing in a thick, almost visible stream over the flaming magnesium torch. The lathe chuck was melting now in the incredible heat of the magnesium's oxidation, the carbon dioxide having had only the slightest damping effect on it, and producing thick clouds of smoke, Norden arrived with a bucket of water and stood waiting tensely.

I'm getting it out, I think," Barren cried out. "This stuff is cold. Ouch." A square inch of Barren's skin stuck to the bitterly cold nozzle of the argon tank, frozen on by the swift expansion of the gas. "Turn off that carbon tank, Horensen. It's just feeding it."

Horensen backed away, looking on in wonder. In about twenty seconds the fire was over, and several large holes had appeared in the lathe bed, fused through. Barren maintained the stream of gas on the still- white-hot metal, as Norden splashed cold water over it. Clouds of steam shot up, hissing furiously. For an instant the magnesium flamed angrily again, then died down as more argon and water cooled it.

"That makes some fire," commented Horensen, moving back with the carbon tank. "Why don't you use sand?"

"That, my lad, is nasty stuff," Barren replied sourly. "Three hours' work gone up in—well, not smoke, call it powder."

"What happened?" asked Horensen.

"Tungsten carbide, hot, will attack magnesium, also hot, in the presence of air and the blasted cement they use. The result is a bit of flame, and when the magnesium starts, it takes a lot of stopping."

"Ja,-that carbon dioxide didn't put it out at all."

Norden shrugged his shoulders, went back to work as Barren set up his machine again.

IT TOOK a week and a half to finish setting up a new apparatus. Barren looked at it doubtfully, and retired to the couch. Norden and Horensen went to bed. Dugan was already sleeping, as usual.

About three hours later Barren got up and went out. Tarragoon was a silent city of the dying. People went about in silent groups, or sat, silent, on benches. Barren walked steadily to the South Lock. He returned presently with a truckman and his truck.

By the time Norden and the others got up, the truck was loaded, and in the lock waiting for them. They ate a hurried meal, and settled themselves in the truck. For half an hour they wound down through the Tarragoon heights, then down and across the Desolation Plains. Forty miles or so out, Norden and Barren set up the delicate apparatus, while Horensen and Dugan unloaded the heavy stuff. finally Norden ordered the truck away, with Horensen, Barren, Dugan and the truckman.

As the truck drove away, Barren walked back from the far side, where he had remained hidden.

"You can't handle all that junk yourself, you asteroid," he announced quietly. "Get down there and take the accumulator controls. I'll take the magnetics."

"What did you do, get out the other side of the truck?" asked Norden in faint surprise.

Barren nodded.

"I know as much about this machine as you do. Get started. If there's any fireworks, I want to be in on it!"

Norden started making final adjustments, then closed the master control with a faint hesitation. Nothing happened. He closed the subsidiary controls, and a brilliant glow of ionized neon and nitrogen appeared around it.

"If that's the best you can do, I can tell you easier ways of doing it," said Barren sourly. "Do you really think this junk can produce any power?"

"I'll have to try a bit higher values, maybe, but something ought to happen, anyway," Barren "said optimistically. He advanced the controllers, and for a moment the ionization died away, abruptly into darkness. Eagerly Norden halted, reading his instruments, watching. The output instruments remained peaceably at zero, the input instruments reading very high.

But as the controls advanced, no change was manifest, save the steady climb of the input. Ionization remained dead, until the very limit was reached. But nothing happened.

"I'm afraid it doesn't work, Dean. Sorry," said Barren more seriously. "Any idea what it might be?"

Slowly, thoughtfully, Norden shook his head.

"Not the slightest. You know I checked it, Gray. We—" he sighed, "that's another for the record. Go call the truck. I'll shut it off."

He looked once more at the instruments as Gray Barren started foot-slogging up the slope over which the truck had disappeared for safety.

"I guess the unknown's going to stay unknown, for all of us, Gray. We've only got about a month to work in now, before the real pinch comes. Hector's winning his fight without a struggle. That's what I hate most. That leech, cutting out our main arteries without anybody even slapping him."

"Well, we'll go back," said Barren disappointingly.

There was a thunderous roar that continued for perhaps half a second

BARREN started off, tramping through the loose drift-snow, toward the little rise beyond which the truck had been parked, safe in case, of an explosion. The winking stars gave faint light, brighter perhaps, than the tiny sun, two and a half billion miles distant even now, at its closest.

His mind was working steadily over the difficulty. Norden's theory had seemed fairly sensible, so far as it went, but the mathematical process that lay between theory and analysis of factors was so vague. It made it—

Suddenly a colossal hand slapped Barren in the back, boosted him over the ridge, and landed him spinning head over heels in the drift-pack on the other side. He rolled halfway down to-the truck. There was a thunderous roar that continued for perhaps half a second, while a frightful blast of energy-light illuminated the scene for miles. The little valley behind him was suddenly smoking, and a wind, hot for this world, was eating holes in the snow so fast he could see it melt. When he reached the ridge, the truck was whining up behind him, slowed, and let him swing on.

The valley was now miraculously free of snow. Barren looked with half-blinded eyes into the star-lit dimness below, beyond the range of the truck's lights. The truck swept down. Abruptly their machine stood stark in its glare. The main-frame of the machine was standing at a crooked angle against a pile of accumulator cases, knocked askew and upset. The control panel where Norden had been standing was riven, completely split, apparently by some kind of discharge. And there was no sign of Norden himself.

"Where is that man?" demanded Dugan hoarsely.

"Strumming a harp on a golden cloud," snapped Barren. "Let's look for the rest of him. Something hit that control panels like a retrograde asteroid, and he was standing right there. He caught a bear in his mouse- trap, and it got mad when he let go, I guess. And—curse it—he was the only man on the planet who could have tamed it."

The truck ground to a halt on bare, naked rock, freed of the over-drift of snow that had hidden them for countless ages. Horensen, Dugan and Barren were out instantly. Barren ran to the control panel at full speed, and wondered dimly as Horensen passed him on the way with a peculiar loping bound that left him standing. Abruptly he slowed as he saw Horensen look at something on the far side of the accumulator stack, and freeze abruptly motionless.

Barren walked slowly up beside him and looked over.

Slowly the blond giant shook his head.

"Them Devils are tough people," said Horensen slowly.

Dean Norden, very much alive, looked up from his seat on an accumulator case, raising his head from his hands, and a slow, broad grin spread across his face.

"I rather envy that fellow Smitty his slide rule. You don't have one with you, Gray, do you?" he asked.

Chapter VIII

Preparing for Hector

VERY slowly, very carefully they, unloaded the wrecked apparatus at Norden's lab. A murmuring crowd of the Devils had collected, and made room for them as they carried it in.

"I haven't the faintest idea what happened," repeated Norden. "The junk just blew up on me after it was supposed to be shut off. A short-circuit probably."

Norden sat down inside the truck and let Barren apply antiseptic to various scratches.

"I always said," Barren grunted, "that that math of yours multiplied both sides by something that didn't belong. From the way it looked, I thought it was zero. My mistake. Must have been infinity."

"The whole thing was wrong. I still don't see where, don't know just what happened. I want to look at the apparatus."

"I've already looked," said Horensen, coming in from the other room. "It looks like Swiss Cheese."

Barren laughed.

"Full of holes?

"Ja—funny holes, and all yellow."

"Yellow," exclaimed Norden. "That was steel!"

"Ja. I know. It was," replied Horensen calmly. "It ain't now."

The two men made a concerted rush for the apparatus. Horensen had swung aside the heavy breech-block. The inside wall was yellow, yellow as cheese, and shot full of little and big holes.

"Now hydrogen," said Barren softly "being expanded as you suggested, should absorb a lot of energy, and then give it off when it contracts. But heat doesn't do things like that."

And heat doesn't send a big purple-red ball of lightning floating up the power leads to a switchboard." added Norden. "And heat just isn't that plentiful—out there. There were thousands and thousands of horsepower in that kick. Most of it was released as radiant energy, and pure heat, in non-explosive forms."

"My God," said"Norden softly, "we're crazy! An expanding hydrogen atom doesn't absorb energy. It releases it! I never thought! We should have seen that. It's a contracting atom that absorbs. Wait a minute; I'll look it up."

From his filing cabinet Norden yanked two drawers full of data and calculations. He brought four standard tables and books from the library, and settled down to the lab bench. Barren left him and moved the apparatus into the other room for study.

Hour after hour passed slugglshly. Sometimes Norden called Barren in, gave him big concentrated lumps of pure brain-fatigue in the form of equations that needed solving, while he plowed on through the main de- rivations.

But Norden felt elated. For gradually the thing was clarifying in his mind. It was a day and a half later, though, before he comprehended in some major portion the operation he had performed out there; the forces he had released.

THEN Barren was hard, at work again, machining, cutting. Norden himself started work on hook-ups of oscillators that seemed impossible, It was the collapse, the first hint of collapse, that started the release, he decided. The complete collapse completed the contraction, and acted to absorb a tremendous amount of energy.

That was the safety-valve, the brake that would stop the engine. What he needed was an oscillation that would build up his fields to the required value, break a little, and buildup again, making an almost steady release of power.

A week and a half was needed to finish the new apparatus, and even then it was not truly completed.

"That thing will eat holes in that lining, just as it did in the steel lining," Norden explained. "I've got something that will stop it though, I believe. But I have to ruin one, to make another. That's why I asked you to make them in triplicate."

"I wonderd how you were going to hold it in."

"'Watch and learn."

"Are you sure it's safe in here now?"

"Pretty much so," Norden replied. "I have fairly good factors on it now."

"Go to it," said Barren. "I'rn taking the magnetics again." Norden took the accumulator stacks.

For three seconds the field built up. Then Norden started his oscillator. Instantly the mechanism glowed with a soft blue light, and the room echoed to a tiny crystalline scraping and ringing, like the sound of crystal hammers beating out silver bells. The apparatus seeined to grow translucent; in its heart they could see a softly glowing wash of red-violet flame that flushed and waned at enormous speeds.

Abruptly the soft, glue light changed to a garish green-and died with a crash of brittle sound. A flash of blue-violet leaped along the cables that strung from it to the second machine, glowed intensely in the heart of the second machine for a hundreth of a second-and died. A biting, reaching cold seemed to radiate from the dark machine they had been operating; it grew more intense. Liquid condensed, froze, then dissolved in more liquid that trickled down the side, to the floor.

"Relapsed atoms absorb," said Barren softly. "What an ice box that would make!"

Norden was opening the breech on the second machine. Barren looked with interest, for the inside was coated with something metallically lustrous, intensely, almost radiantly blue, like the wings of tropical butterflies. Barren looked at it silently.

"Where in blazes did that come from, and what is it?"

"The other machine. It's the changed lining. It's contracted beryllium. It plated out."

"Plated out? How in heck did beryllium atoms travel through a wire?"

"Contracted atoms. I reversed the polarities at the end, feeding on the previously released energies, and the protons and electrons were contracted instead of expanded. Contracted to-neutrons, maybe. At any rate, something incredibly minute, and incredibly dense. The electrons are massive as protons in that, and small as protons. Theoretically I should be able to get pure, safe power from it. Power that we need to save Pluto. I'm going to try."

"How much?"

NORDEN shrugged.

"I couldn't tell. But I've got an automatic relay system hooked in to cut it down when the first accumulator bank there is charged, to what should be idling, mere maintenance power. If it is still turning out power, and fills the second bank, it will be shut off. If the relays are slow, it has the third and fourth banks to fill up before anything happens. An oscillograph with a cathode ray working on a megacycle note will time it to a millionth of a second."

"Hm-m-m," said Barren doubtfully. "How about those leads? All right, go ahead."

Norden was starting already. The fields built up, and the oscillator cut in. The oscillator relay thudded, and, it seemed, simultaneously a wave of heat, a smell of burning rubber, and a thunking of a pair of relays followed. The machine stopped almost as soon as it started.

Norden drew back sharply.

"Your relays are as slow as hell," Barren observed. "The fourth bank's half full," he said drily, turning the carbon dioxide eittinguisher on the burning rubber of the cable insulation. "These things are red hot, by the way."

Norderi wasn't paying any attention. He was developing the cathode ray plate. The instant it cleared in the solution, he held it up, unfixed.

"The first bank filled in seven and a quarter seconds, pal."

"You mean," corrected Barren, "millionths of a second, I believe. If it filled the banks at the rate of one every second, that meant three hundred and fifty-two horsepower in a tenth of a second. He looked at the little thing in awe. "I wonder why it didn't blow up those cables?"

"Their heat was taken up in the process," Norden pointed out. "That's one of the things about it. While they were carrying the greatest current, they were automatically at absolute zero—super-conductors. It was only the residual currents, after the process was stopped, that heated them. And now, let's move down to the Central Plants. I'm beginning to see how we can battle Hector."

Chapter IX

Take-Off

BARREN mopped his brow. The Dome was altogether too hot. Also, too noisy. Every light in the place was burning, every machine in Tarragoon seemed going. The air, which had been a bit thin because of the lowered oxygen content, was overly rich now, with a heady, exhilarating effect.

Dugan wore a broad grin.

"The people here are happy now, eh!"

"To hell with that," retorted, Barren. "They're still sending the boys out from Earth," said Barren grimly. He turned to Horensen. "What I want to know is, will your ship take that stress?"

"Oh, ja. That's emergency acceleration, and we won't be loaded."

"How soon are they going to have more of those machines ready, Dean?" Barren asked abruptly.

"Oh—the machines," Norden repeated, looking up from his work. "Two a day. They're putting four in Horerisen's ship for drive, and two more for power. They'll have to make another one for the projector. Those guys in space, whoever they are, will find plenty to wrestle with if they try to stop us!"

"Did you melt that contracted beryllium?"

"No. I think it's a gaseous form now, held by pure gravitational attraction so it appears solid. In that case it wouldn't have a melting point. It will just volatilize slowly at about 5,000 degrees centigrade."

"Then that other thing will work?"

"Oh, beautifully."

"Ah," said Barren delightedly. "Hector's about to catch himself a wooden horse. Come on, Horensen. They're putting in those tubes, and I want to see them do it. Coming, Dean and Tom?"

HORENSEN'S ship was surrounded by a crew of lean, tough hill-devils, working at it with a grimness curiously foreign to the atmosphere of Tarragoon now. Tarragoon was rejoicing, and with her rejoiced all Pluto, save these men, and those who relieved them when they tired. Technicians were obeying blindly the orders Norden had given them in the placing of strange engines, engines they knew nothing about.

The rocket tubes that had been made of tungsten alloy were being converted now, by a slightly different process, to the contracted state. One after another they glowed intensely blue, fearfully cold, then relapsed into the new state, impregnable to the vicious assaults the tremendous energy released through the new rockets would subject them to.

Barren busied himself balancing strange circuits, wiring new controls. He watched with interest while a new type of welding torch flamed viciously blue and fused stubborn beryllium plates and beams instantly, welding a new device to the nose of the ship. It was, something blue and lustrous, with a greenish, scintillating transparency that seemed like a lens at the front of it an egg-shaped thing two feet in diameter, three feet long. But even Barren, tireless giant that he was, had to rest finally; He returned to the laboratory and lay down, closing his mind to thought and action as he had learned to do. But not entirely to thought.

He thought anxiously of the people on the Trojan Worlds capturing Horensen's ship, dragging home the Wooden Horse in deadly triumph. Well, they would find a surprise waiting for them!

The ship was quiet when he returned, after seven hours. Only a few things remained to be done. Tons of water were being pumped into the great mass-fuel tanks. In the tail power room, four of the new generators idled, in readiness, glowing softly, silently. In the nose rocket room, three generators stood ready, one for the new projector, one for the field projector, one for the nose rockets. The ship blazed with light.

Horensen saw him poking about the ship, investigating.

"Gray, I think you should take her home. You know better. You don't sleep."

Gray Barren shook his head.

"No, skipper. You're pilot of this ash-can, Horensen. I'll join under you as Chief Assistant, since my own ship is wrecked. But the Line made you pilot, and I can't take that over."

"Ja. You be Chief Assistant. You'll take that ship home—starting in four hours. Norden and Dugan will come with us."

"Four hours? Right!"

IT WAS a new kind of take-off. The rocket gases came out invisibly, soundlessly, only forming red flame a thousand feet behind. The shrill scream of the gases did not sound at the ship, but a quarter of a mile behind her. And the ship leaped into the air and out into space as no ship had ever left Pluto before. The discharge gases were leaving the rocket-nozzles at an average velocity of 10,000 miles a second, as hydrogen and oxygen ions, not molecules.

Barren, plastered into his seat by an unexpectedly violent acceleration, retarded the controller a fraction of an inch and felt the drive ease perhaps two gravities.

"Don't be impatient, baby," he murmured, "we have a long way to go yet."

He turned to Horensen.

"We're free of Pluto now. I'm going to put it on two gravities and just let it roll. No danger of the fuel giving out?" Barren ended.

"Emphatically, no! The fuel tanks are full, and designed for a mile per second discharge rate, and we've boosted that ten thousand times."

"All right. She stays there then. How long will it take us?"

"At two gravities? It's 2,800,000,000 miles to the sun, less about 500,000,000 for Jupiter's orbit—approximately 550 hours if you accelerated positively all the way—"

Dugan jerked upright.

"What? What did you say? five hundred and fifty hours! It would take two years at sixty miles a second! How is such speed possible?"

"Right! But, Tom, you'd wind up making about six thousand miles a second this way, when you reached Jupiter's orbit. You'd sail past Jupiter so fast you'd have to start using the past tense about it before you really saw it. We'll have to make half the trip—say twelve hundred million miles, accelerating. The other half we'll have to decelerate. That means"—the slide rule worked overtime—"three hundred and ninety hours to mid-point, and another three hundred ninety slowing.

"Call it eight hundred hours. I'll have to figure it accurately on the charts, but that gives you an approximation," he said airily.

Horensen whistled in amazement at the miraculous figures.

A month would see this trip done! A month, where two years had been needed before. A corps of men worked still inside the ship, and the men practiced their new duties. Furiously Norden spent his time calculating, and some few new minor devices were 'incorporated'in'the ship in flight. So many things this promised!

Barren flung his ship on, faster and faster. For fifteen days, he hurtled the ship through the void at a pace no man had achieved before. The rocket-tubes glowed an incandescent violet, so hot only the weird, contracted tungsten could endure it. Steadily they whispered with a dry, crystalline rustling, like a lizard army on desert sand. Never the full-throated bellow of the baying ships of space of old. This was a ship of the new era, a ship of silence broken only by the crystalline tinklings and dry rustling of inconceivably hot elements in the maws of unnatural element tubes.

For fifteen days the braked, while the sun expanded "below" them, and the Minors rushed nearer, and Jupiter's orbit grew close. High "above" it, far over the orbital plane, they flung over it, and beyond the asteroid belt. They reached a stop, well inside, out of range of any instruments the Trojans might have. Then they reversed, and the rockets whispered as the ship leaped through space, headed now in the regular rocket route to Pluto, going slowly, as a regular rocket might.

And the gently operated rockets were flaming now with ordinary hydro-oxygen flames.

The Wooden Horse was ready, drawn up in line, and waiting to be hauled within the gates of Troy!

Chapter X

Battle in Space

HORENSEN, Norden, Dugan, and all the others strapped themselves into bunks. Grimly Barren watched his controls, and the little tell-tale apparatus they had rigged that would announce an attack. The Trojan Worlds appeared dim flecks of dust on an infinity of black velvet flecked with silver and gold of stars.

Hour after hour Barren sat, quiet and tense. Most of the men had fallen into natural sleep; only Norden and Dugan had stayed awake, talking to him, his living indicators. For when they would fall asleep, suddenly, he would know—

"Do you suppose they've stopped collecting ships?" asked Norden at length.

'No, I don't see why they would. For that matter, why should they?"

"They might have thought of event-u-al—"

Barren looked at Norden, closed his left eye, elevated his right eyebrow, and said softly: "Oh, yes?" He looked at the instrument board. The radio-frequency ionizer,was flaming now, long violet, flames that niade no sound, gave no heat.

The ship coasted free, inert. Keenly alive, Barren watched. For minutes nothing whatsoever happened. Then a faint, gentle acceleration gripped him, pressed him lightly to his seat. Evidently, the puller was behind him. Cautiously he set the gyroscopes to turning the ship very slowly, very very slowly, so that it might appear to be an accident of mass distribution.

Far away, dimly visible as minute specks of light, Barren saw two little ships. The acceleration grew, became pronounced. Soon it was a powerful stress throughout the ship, and the speed was falling rapidly. It was nearly a two gravity pull now. It held constant at that, and slowly the two ships drew nearer, expanded from points of light to two sets of multiple lights, expanded further to dimly visible ships pulling the interplanetary freighter nearer, slowing it for a landing on the Trojan worlds.

For hours Barren sat grimly motionless, letting his ship be pulled towerd the worlds, toward the ships. They came no nearer than a half mile, two two-hundred foot spheres with rockets dimly visible now. They were pounding heavily now; the tremendous tractor beams carried the throb of their rockets to him.

The Trojan worlds began to approach now, drawing nearer and nearer. It was some time before Gray Barren made out the few dim lights visible on the worlds, toward which they were headed now. They were miniature worlds, from a hundred to one hundred, and fifty miles in diameter, rotating slowly about each other. They were nothing but bare, oversized rocks in the void, only vaguely spherical.

The two towing ships separated, letting the lifeless transport sink down between them, toward the tiny world they approached. Gray Barren sat motionless. Tow beams gripped his ship again, more gently, and very gingerly lowered the vessel down, down to the surface of the tiny planet.

It landed with scarcely a jar, perhaps half a mile from a dull-gray metal dome set with half a dozen small lighted windows in an expanse that must have covered three square miles. A huge lock faced the ship as it lay inert on the ground, and, from it, a tractor machine advanced silently, into the vacuum of space.

The tractor beams of the space ships had ceased now. Eagerly, grimly intent, Gray Barren looked at the tractor as it came nearer. There was a housing that evidently concealed its operator, but even that cab was sheathed in dull metal, with a tiny shining window that offered only a trace of vision.

THE Wooden Horse was being moved, moved within the physical gates of this Trojan city, as in the mythological legend. The great lock-doors opened in orange-peel sections. Like an ant lifting some great lump of dead food the little tractor clamped a powerful magnetic grapple to the hull of the ship, heaved mightily, and the two hundred thousand ton mass rode on the twenty ton tractor. Slowly it moved toward the lock, through the gates. Barren watched in his periscope, as the orange peel sections swung to and locked behind him. Still he had seen no member of this race whatever they might be.

The inner lock, a small door, opened, and a score of machines came in, each a tiny rocket ship in itself, moving easily in this light gravity to a position on the hull of the giant ship. One made directly for the ship's lock as the tractor put the ship down on the dull-gray metal floor with a dull, heavy clang.

For the first time in hours, Barren shifted. He wondered if Norden or the others had wakened, now that the sleep-beams must be off. He called sharply. The men slumbered heavily, drugged with sleep.

"The time has come, the walrus said—" quoted Barren from Lewis Carrol. His hand touched a stud, flicked over. A low crystalline murmur started, a control moved under his fingers. There was a sudden fluttering, scurrying of the tiny rockets outside, and a swift general retreat. Barren heard a heavy grinding at the lock portal, and at the same time pulled down the release of his weapons.

Red lenses in his goggles protected his eyes. A beam of pure green light, a beam of unimaginable energy, lashed out at the small lock door down there. In an instant the door was smoking, in half a second it glowed red-hot. In two seconds the white-hot metal melted.

The beam impinged on the further lock door. Something organic flashed in a sudden flare of intense white, then vanished. The inner door hesitated, heated to whiteness, and puffed inward. A roaring of air set up, a roaring as of a mighty organ pipe, and Barren moved his projector. The dense atmosphere of Jupiter was inside there.

A beam, two feet across, tore at the metal of the outer lock door, to be joined an instant later by a rocket blast from the stern rockets that nosed the ship abruptly against the forward lock wall. The flying ions roared at the lock door, and in three seconds it exploded outward. Barren opened the nose rockets a bit. The enemy's dome was rising to hectic life. A flashing of moving lights, dimly seen through the murky air within, told of frantic haste.

The Wooden Horse backed out of the lock, out into open space. A half mile from the lock, two space ships roared down at it, their rockets flaring, and Barren's radio ionizer flamed again with high violet flares. Grimly Barren turned the great ship on its gyros, lined it carefully on the nearest of the ships darting toward him, and pulled back the main release of the field projector.

SUDDENLY the attacking ship exploded in a wash of unbearable flame. The great dome below felt the savage blast of heat. Barren threw his hands across a face seared by vicious ultra-light, flipping a control to "Emergency." The ship leaped up, away from the miniature world. Far faster the desperate Trojan ship leaped after it.

Barren swung his ship on its axis. Racing backward now, he released the energy of the projector. Dimly he could see the incandescent glow, of the contracted-beryllium egg. He saw the enemy ship brilliantly flaming in its heat. Like a dancing mosquito it dodged, swung erratically, wavering away. Presently it came back under control, and little gouts of flame appeared on its sides. Barren grimaced, and turned his field projector to maximum, the wide-spreading cone like a shield between him and the Trojan guns.

The Trojan ship seemed diseased. It was wandering erratically, and, as he watched, Barren saw great masses of the dull-gray metal slough away, like the rotting flesh of a leper. Bare bones appeared, and white lights that winked once and vanished.

The derelict rolled trundling on toward the sun as Barren maneuvered his own ship to one side. It was a short-lived derelict, for, far below, Sol's quarter-million mile tongues of flame reached out to it.

Gray Barren's mouth had a curiously set grin on it as, the last of his major enemies removed, he started circling back toward the dim domes on the Trojan Worlds.

Chapter XI

The Chain Is Welded

NORDEN muttered sleepily, groggily at Barren's misty face.

"Come on, Rip. Breakfast time I think," came Gray's chaffing voice, dimly "heard through the cotton of sleep. "How about some ham and eggs? Or sausage and hotcakes?"

"Eh?" snapped Norden sitting up abruptly. "What? Sausage?"

Barren roared.

"Yes, my love. Sausage. Sausage and hot-cakes with maple syrup, and hot coffee. And maybe a thick piece of apple pie. We'll hit Denver field in about an hour, and I want your help. I can't run this ash-can and pound brass at the same time. Turn to on Horensen and Dugan while I go hack to the board. We're moving a bit fast."

Norden looked out of the window. Blank space. But the periscope screen showed Earth, great and greenish streaked with clouds. A vast smooth plain of greenish water, a vast rough corrugated roof of land, it was a heartening sight.

"Earth!" he gasped. "I haven't seen it in twenty years!"

"Seems like twenty centuries since I've seen it last," said Barren. "I'm maintaining a half g for ten minutes. Haul Horensen into the Wash room, and dump him in the tub. The water will probably bring him to. Then do the same with Dugan. You had six days to sleep it off."

"Six days!" gasped 'Norden. "I—I just went to sleep." "Ask Hector about it. He'd say different. And I ought to know too, for all of that. By the way, I, met Glenn Purdy in the 453 on the way in. He's turning back, and ought to land in about three weeks."

Norden hauled Horensen out of his bunk, and walked to the rear with him. Presently there was an explosive splash, and much explosive language. A minute later a dripping Horensen came in, muttering. But he picked up Dugan with a peculiar look of satisfaction and went back with him.

"What happened, Gray?" Norden asked. "The last I remember we were talking to you. I-said they might have stopped collecting ships; fearing eventual attack."

"So you were. That was some seven days ago, Dean."

"It was thirty seconds ago in my mind."

"They hadn't, needless to say. They collected us, took us right into one of their domes on a Trojan world. I think they originally came from Jupiter. They certainly had thick enough air."

"What do they look like? Anything like us at all?" questioned Norden.

Gray Barren shrugged.

"They don't display themselves. I never saw one of them. They stayed behind metal except when I took the metal away. That's one thing about those toys you gave me. When they remove something, it stays removed, and takes rnost of the background with it. When I cut open a ship, every creature in it vanishedin the cutting process. It's like trying to open an oyster with a two-pound stick of dynamite. It opens the oyster fine, But it's hard to find the oyster afterward. I'm afraid we'll never know what they looked like. Maybe—some day—some year—we'll find out!"

"How many ships were there?" asked Horensen.

"Two," answered Barren. "Say, Horensen, suppose you start pounding the wireless over there. You know about what to tell 'em on Earth."

"Ja. But they won't believe it's me. I'm not supposed to come back for a year and a half yet," he chuckled. Then, more seriously, "Did you ruin those Trojans, boy?"

"Somewhat. They're tamed for a while. I met Glenn Purdy on the way in, and sent him back home."

"Glenn Purdy. Let's see. That's one-two-three-ach, an unlucky number. Thirteen!"

"Yes. Unlucky. For them. They got those others though, Horensen. But they're through now. They had domes on seven of those Trojan Planets, strung along the sixty degree group. I haven't gone after the other group yet! I'm saving that. Some of the other boys may want to come along."

"You're the only one that can do the job, though, Gray," said Norden.

Barren shook his head and grinned.

"Snap that lever there, Dean."

Norden looked from his friend to the little blue stud. He flipped it over for an instant-and slumped heavily in his chair. Barren reached over and snapped it back. He shook Norden vigorously for a moment. The physicist opened his eyes.

"Whew—it hit me like a sand-bag," he said softly.

"It's easy now," Barren told him. "I got quite an analysis run on it while one of the domes was trying to lullaby me. Unfortunately I never could tell a lullaby from a waltz, but I did figure out some characteristics. I spent three nights—need I say sleepless nights?—figuring out what it meant, though. They fix those waves beautifully, and they do funny things. One type had me vomiting for fifteen minutes straight. It attacked the olfactory centers in a most ghastly manner. They have some interesting tricks."

"But what happened?"

"Plenty, you ought to see that cone of yours in action, Dean. It gives the grandest sort of protectign against any type of explosive torpedo, shell or bomb, and at the same time it will give a whole world or a ship leprosy. Those planets got sick and died, and their skin sloughed off and they rotted before my eyes. Disgusting sight. But the Trojans didn't like it, nor the Wooden Horse they'd dragged home. I spent two days trying to find energy releases around there, locating domes and ships and hideaways. They don't like us any more."

"Did you kill them all?" asked Horensen.

"All I could find on those planets. Jupiter's pretty big though, and I fear it's crawling with them."

"Did they try to parley with you?" asked Norden slowly.

Barren shook his head.

"That surprised me. They attacked me steadily as long as their planets and their machines held together. They have little, individual rocket ships, and they tried to drive them through the ship. I think they know only one law-might. Force. Battle. They probably feel themselves quite justified in taking those ships, because they could. They probably don't feel annoyed greatly that we wiped out those domes.

"But I came back to Earth to prevent more men running into that trap, and to have Earth make a fleet of these Wooden Horses. Might may make right—but they won't be easily convinced they still haven't might. Jupiter's the mightiest planet of the system.

"So we must send several ships like this, and remove the Trojan lglanets and send some experts who can confab with them, and show them sense. I think a few of their beams, modified to affect different nerve centers, might help us.

"But we have power, and we know they want power. So we must have the Might now, thanks to you, Dean."

"Ja, I think we take them for a ride," Horensen said slowly, quite pleasantly. Horensen's sunny blue eyes somehow, without changing in the least, had become as blue as sapphires.

"And incidentally, you saved Earth a bit of trouble, as well as Pluto, I suspect, Dean," Barren said sincerely. "They wouldn't have been satisfied with robbing supply ships indefinitely. They's want the mother lode, eventually. But Pluto will know better what your work meant, for they saw the sun very far away, and Jupiter very, very close, those last few months. Now they have the sun at home, on Pluto itself, in neat, little boxes that will warm them forever and power them forever."

Norden sighed.

"They won't love me long. You can transmute with these things—and the Earth won't pay Pluto for its caesium long or its plutonium, or other heavy elements, and Pluto won't be a harsh frontier. Those hill-devils are frontiersmen. They won't appreciate the easement of the last frontier."

"You're wrong. He who said a prophet is not without honor save in his own country, may or may not have been a god, but he was a psychologist. Those hill-devils are my friends, and I know them. Society has no place for them, save on the frontier. They're useless misfits now."

Barren cocked an eye at Norden.

"Yes?" he said slowly. "The last frontier is gone, you say. You don't understand human nature as well as you think. The last frontier is never gone. It's always, by definition, one step farther than society has gone. This ship could operate at two, full gravities' acceleration for two years. How far, Norden, would that take you."

"Why—nowhere," Norden said casually. "Out of the Solar—" Norden stopped suddenly, and his eyes seemed to gleam to the tiny lights of far-off, challenging stars. For men like Gray Barren and himself would never rest until science had charted the last outpost in the cosmos.