It was a crisp, clear morning in the city of Copia. A cold winter's sun glinted on the myriad roof tops of the vast spreading metropolis. To the north, snow-covered hills gleamed whitely, but the streets of Copia were dry and clean. There were not many people stirring at such an early hour. The dozen broad avenues which converged like the spokes of a great wheel on Government City in the center of Copia were quite deserted. There was little apparent activity around and about the majestic Government buildings, but the four mammoth gates were open, indicating that Government City was open for business.

At the north gate the sentry, sitting behind his black panel with its clusters of little lights, switches, and push-buttons, glanced upward. There was a faint humming and a man was circling downward about a hundred feet above him. The rays of the early sun flashed off a helmet and the sentry knew that this man was a soldier. The newcomer dropped rapidly, the stubbed wings on his back a gray blur. Then the humming ceased as the soldier switched off his oscillator and landed lightly on the ground before the sentry.

The sentry's swift glance took in the immensely tall, broad-shouldered figure, covered to the ankles in the green cloak. He took in also the pink, smiling face and merry blue eyes, and the lock of bright red hair which showed as the soldier pushed his helmet backward off his forehead.

"Your business?" asked the sentry.

"I have orders to report to the Commander-in-Chief," said the soldier, with a pleasant smile.

"Let's see," said the sentry, glancing at the insignia on the helmet, "you're a decurion of the Eightieth Division. And the name?"

"Dynamon," said the soldier.

"Oh, yes," said the sentry, with a recollective smile, "I remember you as an athlete. Didn't I see you in the Regional Games two years ago?"

"Yes," said the soldier, with pleased surprise. "I was on the team from North Central 4B."

"I thought so," the sentry chuckled. "As I remember you walked away with practically everything but the stadium. Hold on a minute now and I'll clear the channels for you."

The sentry bent over the panels, punched some buttons, threw a switch, and recited a few words in a monotone. He listened for a moment, then threw the switch back and looked up.

"It seems you're expected," he said, "third building to the right and they'll take care of you there."

Ten minutes later Dynamon stood in the doorway of a large, beautiful room and saluted. The salute was answered by a grizzled, dark-skinned man sitting behind an enormous desk. This man was Argallum, Commander-in-Chief of the Armies of the World. He rose and beckoned to the young soldier.

"This way, Dynamon," said he, opening a small door. "What we have to talk about requires platinum walls."

Dynamon's face was a mask as he followed the Commander-in-Chief into the little room, but his heart was pounding and his mind working fast. The platinum room! That meant that he was about to learn a secret of the most vital importance to the world. He remembered now, that there was a delegation of Martians in Copia. They had arrived about a week before, ostensibly to carry on negotiations in an effort to avert the ugly crisis that was developing between Earth and Mars. But the conviction was growing among the citizens of Copia that the chief object of the Martian delegation was to spy. It was a well-known fact that the grotesque little men from the red planet had a superhuman sense of hearing that seemed to enable them to tune in on spoken conversations miles away, much as human beings tuned radio sets. They could hear through walls of brick, stone or steel; the one substance they could not hear through was platinum. Hence the little room off the Commander-in-Chief's office which was entirely sheathed in this precious metal.

Argallum sat down heavily behind a little desk and gestured Dynamon to be seated opposite him.

"On the basis of your fine record," said Argallum, "I have selected you, Dynamon, to lead a dangerous expedition. You may refuse the assignment after you hear about it, and no blame will attach to you if you do. It is dangerous, and your chances of returning from it are unknown. But here it is, anyway.

"The situation with Mars is growing worse each month. They are making demands on us which, if we accepted them, would destroy the sovereign independence of the World-State. We would become a mere political satellite of Mars. But if we don't accept their demands, we are liable to a sudden attack from them which we could not withstand. They have got us in a military way and they know it. We might be able to stand them off for a while with our fine air force, but if they ever got a foothold with their land forces, then it's good-bye. They have a new weapon called the Photo-Atomic Ray against which we have absolutely no defense. It's a secret lethal ray which far outranges our voltage-bombs and which penetrates any armor or insulation we've got."

"Now, of course, our Council of Scientists has been working on the problem of a defense against the Ray. But the only thing they've come up with is a vague idea. They believe that there is a substance which they call 'tridium,' which would absorb or neutralize the Photo-Atomic Ray. They don't know what tridium looks like, but by spectro-analysis they know that it exists on the planet Saturn. So I am sending you with an expedition to Saturn to find, if you can, the substance known as 'tridium,' and bring some of it back if possible."

"Saturn!" gasped the decurion.

"I said it would be dangerous," Argallum said, bleakly. "No human being has ever set foot on the planet, and very little is known about it. But that's where you'll find tridium, if we're to believe Saturn's spectrum. You will have the latest, fastest Cosmos Carrier. You will have a completely equipped expedition. You will have for assistants the best young men we can find. As head of the expedition, you will be promoted to the rank of centurion. Do you accept the assignment?"

"Yes, sir," said Dynamon, unhesitatingly, "I accept the assignment."

Dynamon walked thoughtfully out of Government city by the North Gate. The sentry noticed that his helmet was now adorned with the badge of centurion, and came to a smart salute. Dynamon went past him without seeing him, and the sentry glared after the new centurion disapprovingly. Lost in thought, Dynamon kept on walking until he came to with a start, and found himself in the middle of the shopping district.

The sun was getting uncomfortably warm and Dynamon switched off the electric current that heated his long cloak and looked around him. A sign in a shop window said, "Only fourteen more shopping days before the Twenty-fifth of December." Dynamon sighed. He wouldn't be around on this Twenty-fifth and it was going to be a very gay one. It was to be the nine hundredth anniversary of the Great Armistice—from which had come the unification of all the peoples of the Earth. Dynamon sighed again.

The long peace was threatened.

The Earth, in this year of grace 3057, was a wonderful place to live in, and Copia was the political and cultural center of the Earth. For nine hundred years now, the peoples of the Earth had lived at peace with one another as members of a single integrated community. The World-State had grown into something which that war-torn handful of people back in 1957 could scarcely have imagined. No longer did region war against region, or group against group, or class against class. Humanity had finally united to fight the common enemies—death, disease, old age, starvation.

And on this nine hundredth anniversary of the Great Armistice, the people of the World would have a great deal to celebrate. Disease was now unknown, as was starvation. Arduous physical labor was abolished, for now, the heaviest and the slightest tasks were performed by machines. Pain had been reduced, both physical and mental. Helpless senility was a thing of the past. Death alone remained. But even death had been postponed. Human beings now lived to be almost three hundred years old.

All in all, Dynamon mused, as he strolled along the broad avenue, the human race had evolved a pretty satisfactory civilization. More was the pity, then, that human restlessness and vaulting ambition should have led to the construction of the great Cosmos Carriers. If Man had been content to stay on his own little planet, then communication would never have been established with the jealous little men of Mars, and this beautiful civilization would not now be threatened by a visitation of the terrible Martians and their frightful Photo-Atomic Ray. Dynamon's deep chest swelled a little with pride at the thought that he had been selected by the Commander-in-Chief to take an important part in the coming conflict.

He turned the corner and found himself standing before an imposing building. Across the top of the facade in block letters was the legend, "State Theater of Comedy." A few minutes later he stood in front of a doorway at the side of the great theater building. The door opened and a tall, lovely girl appeared.

"Dynamon!" she exclaimed, "I didn't expect to see you for another ten days." She stepped out of the doorway, and reached her arms up impulsively, kissing Dynamon.

The tall young soldier gripped her shoulders hard for a minute, and then stepped back and looked down into her soft brown eyes.

"Yes, I know, Keltry," he said soberly. "I had to report on short notice."

"Oh!" said the girl called Keltry, "are you here on duty?"

"Very secret duty," said Dynamon with a meaning look. He twiddled an imaginary radio-dial in his ear and looked around mysteriously.

The smile died on Keltry's smooth brown face, to be replaced by an expression of concern.

"You mean—them?" she whispered.

Dynamon nodded. "Yes, I am being transferred to a new post," he said slowly, "and I thought, if you had no objections, I would ask to have you transferred along with me."

"Do you need to ask a question like that?" said Keltry. "You know perfectly well I'd have a lot of objections if you didn't ask for my transfer."

"There may be some danger," he said, giving her an eloquent look.

"All the more reason why I should be with you," Keltry said quietly.

Four days later, a conference was breaking up in the platinum room behind the Commander-in-Chief's office. Argallum stood up behind his desk and carefully folded a number of big charts. He laid one on top of another, making a neat stack on the desk, then he looked keenly at the four young men standing before him.

"Once more, gentlemen," Argallum said, "for the sake of emphasis, I repeat—Dynamon has complete authority over the expedition. You, Mortoch"—looking at a lean, hawk-nosed man in a soldier's helmet—"are in command of the soldiers. And you, Thamon"—turning to a studious, stoop-shouldered man—"are in charge of civilian activities. And Borion"—glancing at a stocky, broad-shouldered figure—"you are responsible for the Carrier. But in the last analysis, you are all under Dynamon's orders. This is a desperate venture you're going on and there can be no division of authority."

There was a moment of silence. Argallum seemed satisfied with the set, determined expressions on the four men in the room with him. "Are there any further questions?" he said.

Dynamon shifted his feet uneasily. "Is the decision—on Keltry, final?" he said huskily.

"I'm afraid it is, Dynamon," said Argallum, gently. "I had the director of the theater over here for half an hour trying to talk him around, but it was no good. He said he would under no circumstances spare Keltry. He said she was the most promising young actress in Copia, and that he would forbid her to go on any dangerous trip. Inasmuch as Keltry is still an apprentice, the Director has full authority over her. I can do nothing."

Dynamon drew himself up to his full height and squared his shoulders. "Yes, sir," he said briefly.

"Very well then," said Argallum, "I won't see you again. You will take off from Vanadium Field promptly at four o'clock tomorrow morning. Every one of the one hundred and twenty-nine people on the expedition has his secret orders to be there at three. Dynamon, you have a hand-picked personnel and every possible resource that our scientists could think of to help you. May you succeed in your mission."

"Thank you, sir," they chorused.

Argallum shook hands separately with each of the four men, after which they filed out of the platinum room.

Outside the War Building, Mortoch, the decurion, and Borion, the Navigator, took their leave of Dynamon and strolled away toward the West Gate. But Thamon, the scientist, fell in stride with Dynamon.

"For your sake, I'm sorry," said the stoop-shouldered scientist shyly, "I mean—about Keltry."

"Thanks, Thamon," said the centurion. "It was a nasty blow. I don't know how I'm going to get along without her. I guess I'll just have to."

"Well—I just wanted you to know," said Thamon, "that I sympathized."

In the middle of Vanadium Field a great gray shape, like a vast slumbering whale, could be indistinctly seen in the soft half-light of the false dawn. No lights showed on the field and no sound was heard. But scores of people clustered around the sides of the Cosmos Carrier, dwarfed to ant-like proportions by its great size. Inside the Carrier, standing near the thick double doors in the Carrier's belly, was Dynamon, near him his three chief lieutenants, Mortoch, Thamon, and Borion. The members of the little expeditionary force filed past the youthful Commander, each one halting before him for a brief inspection. One hundred brawny soldiers, divided into squads of ten, stepped through the double doors, each squad led by its decurion. Dynamon ran a practiced eye over the equipment of each man and then for good measure turned him over to the scrutiny of the Chief Decurion, Mortoch. Then came twenty-five civilians, including ten engineers, four dieticians, five administrators, and six scientists. But for a cruel prank of fate, Dynamon reflected, his own dear Keltry would be a member of the expedition.

But there was no time for regretting that which could not be. Dynamon turned and walked toward Borion.

"Are you satisfied?" he asked the navigator. Borion nodded, and Mortoch and Thamon likewise nodded in answer to Dynamon's unspoken question.

"All right," said the young centurion. "Stations!"

A moment later the great outer door of the Cosmos Carrier swung silently shut, after which the thick inner door was secured and the great ship hermetically sealed. Dynamon followed the navigator into the control room.

"This is a gorgeous ship!" said Borion. "It's absolutely the last word. There's a cluster of magnets underneath our feet that are brutes and yet they can be so finely controlled, I'll guarantee you won't feel a bump at any time. Dynamon, these magnets are so strong that this ship will go at least ten times faster than anything that has yet been built. Once we get up out of the stratosphere, beyond the danger of friction, we can go almost twenty miles a second. You ready for the take-off? If you want to use the loud speaker system just throw that switch."

Dynamon nodded; a moment later his voice was heard in every compartment of the Cosmos Carrier.

"Men, we are taking off. Hold your stations for five minutes, after which you may take your ease until further commands."

"Come and watch the altimeter," Borion said after Dynamon closed the loud speaker switch. "You won't believe we're off the ground, these controls are so smooth." The centurion watched the needle creep gently upward a few feet at a time. But he could feel no trace of motion.

"I'm going to take her up vertically to two thousand feet," said Borion. "Then we'll be clear of all obstacles and can pick up our course horizontally—"

"Yes, good," Dynamon broke in quickly, "but don't tell me your course until we are out of the stratosphere."

"Aye, aye, sir," said Borion with a wink, "little pitchers have big ears, don't they?"

"How soon will we get out of the stratosphere?" Dynamon asked.

"Well, I'm lifting her very slowly," answered the navigator, "I don't want to take any chances on friction. I would say in about three hours from now we will be ready to go."

"I will be with you then," said Dynamon, and walked out the door.

The young centurion had in mind to make a thorough inspection of the entire ship, but he had scarcely been ten minutes away from the control room when the loud-speaker system boomed forth.

"Centurion Dynamon is requested to come to the control room." Dynamon hurried up a metal staircase and then through a companionway. As he threw open the door to the control room, Borion turned quickly and laid a finger on his lips. Then the navigator gestured Dynamon toward a series of glass panels. There were six of these panels, each about a foot square, and ranged in two vertical rows of three each. One word, "periscopes," was stenciled at the top, and beside each mirror were other labels, "port bow," "port beam," "port quarter." The other three panels were labeled in the same way, designating their location on the starboard side. Borion flicked the switch beside the "starboard quarter" panel and it become dimly illuminated. Dynamon threw a swift glance at the altimeter, and saw that it said two thousand feet. Then he bent over and peered into the periscope panel. A wide panorama of twinkling lights spread out before him, the street lights of Copia. But the pale blue of approaching dawn was creeping fast over the city, shedding just enough light to reveal a dark shape a mile behind the Cosmos Carrier, and perhaps a thousand feet below. As Dynamon stared into the periscope screen, he thought he could detect a faint glow of red in the following shape. He turned questioningly to Borion. The navigator was writing rapidly on a piece of paper. A second later he handed the paper to Dynamon. It said:

"I queried Headquarters and was told that the conference with the Martian delegation is still officially going on. But that Carrier following us is bright red, the color of the Martian Carriers."

Dynamon held the piece of paper in his hand for a minute and gazed doubtfully into the periscope screen. Then he took the pencil from Borion and, bending over, wrote the following:

"I don't like the looks of this. Can we out-run them once we get out of the atmosphere?"

Borion nodded slowly.

"As far as I know, we can," he said, "unless—" he reached for the paper in Dynamon's hand and wrote "—unless they have developed a new wrinkle in their Carriers that we don't know anything about."

"Well," said Dynamon, "we won't waste time worrying about things over which we have no control. Proceed as usual."

There followed some anxious hours, which Dynamon spent with his eyes glued to the periscope mirror. In a short time the early golden rays of the sun appeared, and the Martian Carrier followed behind inexorably, glowed an ugly menacing crimson. Once Dynamon instructed his communications officer to speak to the Martian ship.

"Lovely morning, Mars. Where are you bound for?" was the casual message.

There came back a terse answer, "Test flight, and you?"

"We're testing, too," Dynamon's communications officer said. "We'll show you some tricks up beyond the stratosphere."

All so elaborately casual, Dynamon thought grimly. It was fairly evident that the Martian ship intended to follow the Earth Carrier to find out where it was going. Those inhuman devils! Why did the Earth's people ever have to come in contact with them?

Dynamon's thoughts went back to his childhood, to that terrible time when the men of Mars had abruptly declared war and descended suddenly onto the Earth in thousands of Cosmos Carriers. Only the timely invention of that remarkable substance, Geistfactor, had saved Earth then. It was a creamy liquid, which spread over any surface, rendered the object invisible. The principle underlying Geistfactor was simplicity itself, being merely an application of ultra high-frequency color waves. But it saved the day for Earth. The World Armies, cloaked in their new-found invisibility, struck in a dozen places at the ravaging hordes from Mars. The invaders, in spite of their prodigious intellectual powers, could not defend themselves against an unseen enemy, and had been forced to withdraw the remnants of their army and sue for peace.

But the unremitting jealousy and hatred of the little men with the giant heads for Earth's creatures was leading to new trouble. It enraged the Martians to think that human beings, whom they despised as inferior creatures, should have first thought of spanning the yawning distances between the planets of the solar system. It was doubly humiliating to the Martians that when they, too, followed suit and went in for interplanetary travel, they could do no better than to copy faithfully the human invention of the Cosmos Carrier. It was only too evident that Mars was gathering its strength for another lightning thrust at the Earth. This time, with the Photo-Atomic Ray, there was no doubt that they intended to destroy or subjugate Earth's peoples for good. And to that end the Martians had been inventing new bones of contention and had been contriving new crises. A peace-minded World Government had been trying to stave off the inevitable conflict with conference after conference. But to those on the inside it was only too evident that the Martians could invent pretexts for war faster than Earth could evade them.

Dynamon, watching the blood-red Carrier in the periscope mirror, felt a surging bitterness at the Martians. If they could only be reasonable, he reflected, if only they could be human, then he, Dynamon, would not now be floating away on a dangerous mission far from the Earth and the woman he loved. He tried to imagine what Keltry was doing at that moment. In his mind's eye he could see her on the stage of the Theater of Comedy, enthralling audiences with her youthful charm as she played a part in the latest witty comedy, or sang a gay ballad in a new revue.

He broke out of his reverie and tossed a glance at the altimeter. The needle was moving much faster now, climbing steadily toward seventy thousand feet.

"It's about time to go now, isn't it?" he asked Borion.

The navigator nodded. "Just about," he said, and put his hand on a lever marked "gravity repellor."

As the navigator pushed the lever smoothly forward, Dynamon turned back to the periscope mirror and saw the red ship behind suddenly dwindle in size. The new Cosmos Carrier was beginning to show its speed.

Apparently, the Martians were momentarily caught off guard. The red Carrier diminished to a tiny speck against the dark background of the Earth. But then it began to grow in size again as the Martians unleashed the power in their great magnets.

"Borion, how about friction?" Dynamon asked.

"We don't have to worry about that yet," was the answer, "we're not going fast enough. And the temperature outside is about sixty-five below."

Dynamon nodded and glanced again at the altimeter. The needle was steadily climbing, a mile every ten seconds. Once again he looked into the screen of the periscope. The Earth was now far enough away so that the young centurion could begin to make out the broad arc which was a part of the curving circumference of the globe. Silently he said a final good-bye to Keltry and turned to speak to Borion. At that moment the door of the control room burst open and an engineer stepped in and saluted the navigator.

"Stowaway, sir," the engineer said. "Just found her in the munitions compartment."

Dynamon stared out through the open door at the woman who stood out there between two soldiers.

It was Keltry.

It was a harried and heartsick centurion who, a few minutes later, called a conference in his own quarters. Borion and Thamon sat regarding him gravely, while Mortoch, the second in command, lounged against the wall, a faint, derisive smile on his lean face.

"We are faced with a situation," Dynamon said heavily. "I would like to hear some opinions."

"Flagrant case of indiscipline," Mortoch said promptly; "that is, if we can regard this impersonally."

"Personalities," said Dynamon sharply, "will have no influence on my final decision."

"In that case," said Mortoch harshly, "it seems to me, you are bound to put back to Earth and hand the woman over to the right people for corrective action."

"Good heavens!" cried Borion, "I hope we don't have to do that. We already have a problem on our hands in the shape of that Martian Carrier."

"What do you say, Thamon?" the centurion asked after a significant pause.

"Well," said the scientist quietly, "you can't altogether regard the situation without considering personalities. Keltry stowed away for a very personal reason, and one which it is hard to condemn entirely. I think we are over-emphasizing the official breach of discipline. I, personally, can't see that it makes so much difference. After all, we on this expedition are on our own and are likely to remain so for some time to come. I am in favor of going along about our business and forgetting how Keltry came aboard."

"Spoken like a civilian," said Mortoch sourly, "and I hold to my opinion. Just because Dynamon was promoted over my head, I see no reason for trying to curry favor with him."

There was an awkward silence during which Dynamon's face grew very pink and his blue eyes grew cold.

"I'm going to forget what you just said, Mortoch," he said. "You are a valued member of this expedition, and you are much too good a soldier to overlook the danger that lies in that kind of talk. Without my participation, you are out-voted two to one. We will not turn back."

He stood up with a gesture of dismissal and the three lieutenants filed out of the door. He paced the floor of his quarters for a few minutes, then walked to the door and gave orders for the prisoner to be sent in.

"Ah, Keltry darling," he said after the guard had left the two of them alone, "you have put me in an impossible position."

"I don't see why it should be that bad," Keltry answered. "It was an inhuman thing to do to separate us and I just wasn't going to permit it."

"Yes, but don't you see?" said Dynamon, "I will be accused of playing favorites because I don't turn around and take you back to Earth."

"I'm not asking favors," Keltry retorted calmly, "I just want to be a member of this expedition."

Whatever Dynamon was going to answer to that, it was interrupted by the loud-speaker booming:

"Centurion Dynamon is requested at the control room."

Dynamon leapt to his feet, crushed Keltry to him in a swift brief embrace and then opened the door.

"Escort the prisoner to the scientist's quarters," he ordered, "and release her."

Dynamon walked into the control room and saw that Borion's face was gray. The navigator was standing in front of the periscope screens looking from one to another. The centurion walked over and stood beside him.

"The Martians are showing their hand finally," said Borion. "They have decided that we're headed for another planet, and I don't think that they want to let us carry out our intention. See, here and here?" Dynamon peered into the port and starboard bow panels. He could see dozens of little red specks rapidly growing larger.

"They will try and surround us," Borion said, "and blanket our magnets with their own."

"That's not so good, is it?" Dynamon murmured. "What is our altitude from Earth?"

"Forty miles," was the reply, "and I think they still may be able to overhear our conversation."

"Let them," said Dynamon quietly, "We have no secrets from them and they may as well know that we're going to out-run them. Full speed, Borion!"

The Navigator advanced the "repellor" lever as far as it would go. There was a slight jerk under foot. Then he adjusted a needle on a large dial and moved the "attractor" lever to its full distance. There was another jerk as the great Carrier lunged forward through space. Borion smiled.

"I put the attractor beam on the moon," he said, "and we'll be hitting it up close to nineteen miles a second in a few minutes. We should walk away from those drops of blood, over there."

"Are we pointing away from them enough?" Dynamon asked. "What's to prevent them from changing their course and cutting over to intercept us? See, that's what they appear to be doing now."

The navigator peered critically at the forward periscope screens. "It may be a close shave at that," he admitted. "But please trust me, Dynamon, I'll make it past them."

The tiny red specks in the periscope screens were growing shockingly fast, indicating the frightful speed at which the Earth-Carrier was traveling. Bigger and bigger they grew under Dynamon's fascinated gaze. The centurion darted a glance at Borion. In this fantastic encounter, every second counted. Could the navigator elude the pursuing red Carriers? Borion haunched tensely over the control levers, his eyes glued to the screens. The Martian ships were as big as cigars now and tripling their size with every heartbeat. Dynamon clenched his fist involuntarily and fought down an impulse to shout a warning. That would be worse than useless now—the fate of the expedition was entirely in the hands of Borion.

Dynamon held his breath as a flash of red flicked across the port bow periscope screen. The Carrier heaved under his feet for a second then quickly settled to an even keel again. The sweat stood out in little drops on Borion's forehead.

"Too close for comfort," muttered the navigator. His eyes widened as another huge red shape loomed up in the starboard bow screen. Borion's hands flicked over a dial spinning a needle around. Then he hung desperately back on the repellor. There was a momentary shock. The Carrier seemed to bounce off something. Borion staggered and Dynamon hurled forward and crashed into the forward bulkhead of the control room.

Then Borion shouted, "We're through!"

Dynamon picked himself up off the floor with a rueful smile. "I thought we were all through for a minute," he observed.

"Well! That was a bad minute there!" said Borion excitedly. "I thought that one fellow was going to get us, but I kicked him off by throwing the beam on him and giving him the repellor. But you can see for yourself, they are far behind now, and they'll never in the world be able to catch up."

Dynamon peered into the port and starboard quarter screens and saw a group of rapidly diminishing red specks. He looked up with a sigh of relief.

"Good work, Borion," he said, and the navigator grinned.

"I don't think we will have to worry any more about the Martian ships from now on, if we're careful," Borion said. "I'm going to run for the shadow of the moon and from there I'll plot a course straight for Jupiter, avoiding Mars entirely."

The door to the control room opened, and a smiling, spectacled face peered in. It was Thamon, the scientist.

"That was quite a bump," Thamon observed. "Were we trying to knock down an asteroid?"

Dynamon gave a short laugh. "No, that was merely some of our friends from Mars trying to head us off. But they're far behind now and we don't anticipate any trouble for a good many days."

"Ah, round one to the Earth people," Thamon observed. "In that case, Dynamon, have you decided how you are going to conduct affairs within the Carrier in the immediate future?"

"Not quite," Dynamon replied. "Suppose we discuss that, in my quarters?"

Thamon nodded. "I'm at your disposal, Centurion."

Dynamon led the way down the little stair and into the compartment that served as his office. Once there, he threw off his long military cloak and sat down at a little table, his great bronzed shoulders gleaming in the soft artificial light.

"I suppose the first question," said Thamon, sitting down opposite the centurion, "is whether to institute suspended animation on board?"

"I think we'd better, don't you?" said Dynamon.

"It would save a lot of food and oxygen," the scientist replied. "You see, even at our tremendous rate of speed now, it will take two hundred and twenty-six days to reach the outer layer of Saturn's atmosphere. Until we actually land the ship, there is no conceivable emergency that couldn't be handled by a skeleton crew."

"Quite right," said Dynamon. "I'll have Mortoch take charge of the arrangements, if you will stand by to supervise the technical side."

"It's as good as done," said Thamon. "We have the newest type of refrigeration system in the main saloon. I can drop the temperature one hundred and fifty degrees in one-fifth of a second. By the way, I was a little worried by that outburst of Mortoch's when we were talking about Keltry."

"Oh, well," said Dynamon, "Mortoch is only human. He was a Senior Decurion and I was passed over him for this job. He couldn't help but be a little jealous. But he will be all right, he's a soldier, after all."

"I hope so," said Thamon, doubtfully.

"Why certainly," Dynamon affirmed. "As a matter of fact, I wish he had been given the command in the first place. Between you and me, I'm not too keen about this expedition to a comparatively unknown planet. Thamon, why on earth weren't human beings content to stay at home? Why did they have to go to such endless pains to construct these Cosmos Carriers? Before these things were invented, the inhabitants of Earth and the inhabitants of Mars didn't know that each other existed, and they were perfectly happy about it. But when they both began spinning around through space between the planets, all of a sudden the Solar System was not big enough to hold both Peoples."

"It's some fatal restlessness in the make-up of human beings," Thamon replied. "Do you realize how far back Man has been trying to reach out to other planets?"

"Well, the first successful trip in a Cosmos Carrier was made seventy-eight years ago," said Dynamon.

Thamon chuckled.

"As far as we know, that was the first successful trip," the scientist corrected. "As a matter of fact, the first Cosmos Carrier was anticipated hundreds of years ago. Just the other day in the library, I found a very interesting account of an archaeological discovery made up in North Central 3A—the island that the ancients called Britain. A complete set of drawings and building plans was found in an admirable state of preservation. The date on the plans was 1956, and as you will remember from your school history, all of North Central by that time had been terribly ravaged by the wars. The inventor, whose name was Leonard Bolton, called his contrivance a 'space ship.' Wonderful, those old names, aren't they? But the most remarkable thing of all, is, that the designs for that 'space ship' were very practical. If the man ever had a chance to build one, which he probably didn't, it might very well have been a successful vehicle."

"That's very interesting," said Dynamon. "Were there any clues as to what happened to Leonard Bolton?"

"None at all," the scientist replied. "All we know about him is that he designed the 'space ship' and then was presumably blotted out by the savage weapons used in the warfare of those days. But, as I say, the remarkable thing is that when we got around to building a Cosmos Carrier eighty years ago, we were able to use several of Leonard Bolton's ideas. Which all goes to show, I suppose, there's nothing new under the sun."

"I'm not so sure about that," said Dynamon with a smile. "I've an idea that we're going to bump into several things new to us on the planet Saturn."

"As to that," Thamon nodded, "I shouldn't be surprised if you are right. Now I suppose I'd better go and make arrangements for the refrigeration job. Will Mortoch be responsible for providing each individual with a hypodermic and return-to-life tablets?"

"That will be taken care of," said Dynamon. "I'll see you later."

Dynamon stood beside Borion in the control room, staring fascinatedly at the periscope screens. The images that were reflected in the six panels made up a composite scene that was awe-inspiring and fearsome. The great Cosmos Carrier was finally arriving at the end of its seven months' journey. In front of the Earthcraft, a vast, barren expanse, uniformly dark gray in color spread for thousands of miles. To one side of the Carrier a wide belt of mist and shimmering particles stretched upward from the planet out toward space. Dynamon realized that this was a small section of the great ring encircling Saturn, that could be seen in the powerful telescopes from Earth. Glancing at the stern vision screens, Dynamon saw the sun twinkling. So far away it was now, that it was hardly bigger than a large star and gave off not much more light. Even though they were coming to Saturn in the middle of a Saturnian day, there was no more than a gloomy half-light to illumine their way.

"Saturn revolves on its axis with such speed," observed Borion, "that I should imagine there will be tremendous prevailing winds on the surface. I think I can see a range of steep mountains down there; it might not be a bad idea if we landed in the lee of them."

"Yes," agreed Dynamon, "I think that would be a good idea. As a matter of fact, we may have to dig below the surface entirely to prevent being blown away. How is the gravitation pull?"

"It's a curious thing," Borion replied. "It should be tremendous but the centrifugal force is so strong that it counterbalances to a certain extent. The ship is handling very easily."

"How soon do you think we'll make the surface?" said Dynamon.

"I should estimate somewhere around six hours from now," the navigator answered. "I could make it sooner but I'm feeling my way."

"That suits me," said Dynamon. "That will give us just time to turn off the refrigeration and bring our people back to life. Lucky devils to be able to sleep through this trip—have you ever been so bored in your life?"

"Never," agreed Borion. "But I am not bored now."

Dynamon walked across the control room and threw a large switch in the wall panel.

"Decurion Mortoch and Scientist Thamon," he said into the loud-speaker system. "Proceed at once to remove the suspension-of-life condition in the main saloon. As soon as everyone is revived, stand by to take landing stations."

As the centurion closed the switch and turned away, Borion called him over again to the periscope screens.

"That is a range of mountains," said the navigator. "I can see it more clearly now. I think I'll slow up our descent a little bit so that by the time we're ready to land it will be midday again. As you probably know, Saturn makes a complete revolution in only a little more than ten hours."

"That sounds sensible," said Dynamon. "We'll need all the light we can get to make a safe landing."

Borion nodded and reached toward the repellor lever. He pushed it gently forward and then looked at his altimeter. He seemed to be dissatisfied with the altimeter reading and pushed forward the repellor lever a little more. Then he looked again at the altimeter, and an expression of bewilderment came over his face. With a muttered exclamation he jammed the repellor lever as far ahead as it would go, at the same time watching the altimeter. Dynamon sensed that something was wrong as he watched the color drain out of the navigator's face.

"The Saints preserve us!" the navigator cried hoarsly. "Something has gone terribly wrong—the repellor isn't working! We're dropping at a frightful rate of speed—!"

Borion leapt to the loud-speaker system and issued rapid orders to the navigating engineers.

"What's going to happen to us?" Dynamon demanded.

"I don't know," Borion said, his face ashen. "I think it is just a simple mechanical failure in the controls from the repellor lever down to the magnets. I don't know how soon my workers can discover the trouble and repair it. In the mean time—"

"In the mean time," Dynamon broke in gloomily, "we may all be spattered all over that gray landscape."

"Either that," Borion gritted, "or we burn to a crisp from the atmospheric friction. I can feel it getting warmer in here already."

Dynamon fought down the sickening sensation of panic that was starting to creep over him.

"How long do you think we have got?" he said with an effort.

"At the most," said Borion staring, white lipped, at the altimeter, "at the most, I should say a half an hour."

The door to the control room burst open and Thamon rushed in closely followed by Keltry.

"I heard you talking to your engineers, Borion," the scientist said rapidly. "Are we in trouble?"

"We are," said Borion, "and it may be the last trouble any of us ever have. Our repellor has gone out for some reason. And we're heading for the surface of Saturn like a meteorite."

"Can't anything be done?" said Thamon.

"My engineers are doing all they can to find the source of the trouble," Borion replied. "But until they do, I can't slow the ship up."

Keltry's great brown eyes were enormous as she moved over beside Dynamon and took his right hand in hers.

"As long as I'm with you, Dynamon," she said in a low voice, "I'm not afraid to die. But I hate to see your expedition fail. Perhaps the fate of the Earth depends on us here in this Carrier."

"I know," said Dynamon, squeezing her hand. His eyes followed Borion as the navigator went to the loud-speaker system again. But apparently the news from below was not encouraging, and Borion's shoulders sagged as he turned to face the other three people in the control room.

"They haven't found the source of the trouble yet," he said dully, "and there's not a thing to be done until they do. I'm sorry that, as navigator of this Carrier, I am plunging you all to your death. But it's a case of a simple mechanical failure which I couldn't foresee."

Keltry stepped forward impulsively and laid her hand on the navigator's wrist.

"Nobody could blame you, Borion," she said gently. "It isn't your fault if the attractor or the repellor lever, whichever it is, gets broken. You are already—"

"Wait a minute!" Borion shouted, eyes darting out of his head. "The attractor! In my excitement I forgot!"

The navigator leapt to the control levers, spun the dial and put his hand on the attractor lever.

"If—I'm only—on time!" he muttered agonizedly. "It's just possible—the counter-attraction of Jupiter—Lord it's hot!"

The control room was silent as death as the navigator eased the attractor lever carefully forward. Dynamon whipped a glance at the periscope screens. The ground was rushing up at a terrific rate, and out behind the Carrier, a dense cloud of black smoke was forming. The veins were standing out in Borion's forehead as he inched the attractor lever forward. The girl and the two men watched him with bated breath as he slowly raised his eyes to the altimeter. A wild incredulous expression appearing on the navigator's face.

"It's—it's working!" Borion muttered hoarsly, "the attractor beam from Jupiter is slowing us up!"

Dynamon's heart leapt and he sprang back to the periscope screens. The column of smoke behind them was still there but it seemed to be thinning out. But the surface of Saturn seemed to be rushing upward just as fast as ever. Dynamon twisted his head around to look at Borion. A feverish smile was lighting up the navigator's face as he pressed forward on the attractor lever.

"We may just make it!" he breathed, and Dynamon said a little prayer.

In the screen a range of dark gray mountains stood out in bold relief and seemed to reach claw-like peaks toward the speeding Carrier. But the smoke had ceased to whip past, and only a small black cloud far behind served to remind Dynamon of the fearful friction that the surface of the ship had been subjected to. At the same time Dynamon felt an invisible force dragging him toward the front bulkhead of the control room, and he knew that the Carrier was slowing up its forward speed. Through the bow periscopes the jagged range of mountains seemed so close that Dynamon almost felt he could reach out and touch them. Miraculously, they rose up to one side of the ship. A moment later a voice sounded in the loud-speaker system.

"The magnet room calling the navigator. A break in the control shaft has been discovered and repaired. Throw the repellor lever into neutral and then advance it."

Borion gave a little sob, flicked back the repellor and then pushed it forward again. The floor of the control room heaved for a minute and then settled on an even keel, Dynamon stared unbelievingly at the starboard midship's periscope screens and saw that the great Carrier was resting immobile not more than twenty feet above the gray soil of Saturn.

"Saved!" cried Borion hysterically, "and it was Keltry who did it! In my excitement I would have let all of us plunge to our death, if Keltry hadn't reminded me that there was such a thing as an attractor lever! Dynamon, Thamon, we should get down on our knees and thank our stars that Keltry was in here!"

The door of the control room opened and Mortoch stepped in.

"Do you have to toss us around like that?" the lean decurion said. "I had a near-panic on my hands with some of those people just coming out of their suspended animation. Oh!—" Mortoch smiled ironically—"I begin to see why we had such a rough passage. If beautiful stowaways are given the run of the control room, I should imagine it would be hard for the navigator to keep his mind on his work."

Borion started forward with a snarl but Dynamon's voice cracked like a whip.

"Attention! Both of you! Try and remember that you are modern, civilized men, not twentieth century brutes."

Borion's hands fell to his sides, and he began to laugh.

"You're absolutely right, Dynamon," he said, "I don't know why I should let myself be annoyed by this crude soldier. After all, the cream of the joke is that Mortoch would never have been able to come in here and make sarcastic remarks about Keltry, if Keltry hadn't been here for the past half hour."

"What do you mean by that?" said Mortoch suspiciously.

"I mean," said Borion, "that if Keltry had not been in here, you and everybody else aboard this Carrier would now be dead."

"Now!" said Dynamon. "I think we have had enough of personalities. Suppose we get a little work done. Mortoch, prepare the First Decuria for reconnaissance duty. Each man should be equipped with cloak, oxygen mask, counter-gravity helmets, and a supply of voltage bombs, and each man's radio should be set at eighty-one thousand meters. Have them ready at the main door in fifteen minutes. I will lead them on a short tour of exploration and Thamon will accompany me. In the mean time, Mortoch, you will remain in charge of the Carrier until I get back."

Dynamon's heart was pounding with excitement as he and Thamon walked through the main saloon toward the group of cloaked figures standing by the big round door. As far as he knew he was going to be the first human being ever to step foot on the planet Saturn. He mentally checked over his own equipment and made sure that it was all in place, including the hard rubber box slung over his shoulder on a strap. That box contained his supply of voltage bombs—little glass spheroids, smaller than golf balls, which, when hurled at an enemy, burst releasing a tremendous electric charge. There was little likelihood that these bombs would be needed, because the periscope screens had shown no sign of life anywhere in the gray, arid valley in which the Cosmos Carrier was lying. However, Dynamon was taking no chances. He glanced briefly at Thamon beside him. The scientist was unarmed, carrying the light metal staff which was the badge of his profession.

Dynamon stepped forward and ran his eyes quickly over the masked, muffled figures of the First Decuria. Then he signed to an engineer who quickly unfastened the great door. Dynamon then stepped through and his party followed him crowding into the air lock between the inner and outer doors. Thamon stepped forward, maneuvered a lever, the outer door swung open and Saturn lay waiting for the touch of Dynamon's foot.

It was not an especially inviting prospect. A blast of unbelievably cold air swirled through the open door, carrying with it particles of fine, gray sand. In the dim, murky twilight, tall gray mountains loomed ominously across the valley floor. Dynamon shivered and turned up the heat in his electric cloak. Then with one hand on the knob of his counter-gravity helmet he stepped gingerly out on to the ground.

Instantly he sank to his knees in gray sand that was as light and powdery as fresh snow. With a quick twist of the knob on his helmet he kicked his feet free and stood lightly on the surface again.

"Attention, First Decuria!" he said into the transmitter of his radio phone. "Adjust counter-gravitation to approximately plus ten pounds."

Stepping backward, he turned and watched the masked figures of his command leave the Carrier one by one. Thamon came out first, followed by the Decurion, and after him the soldiers. Mechanically, Dynamon counted them. As the tenth soldier stepped out on the gray soil, Dynamon started to turn away when to his astonishment an eleventh cloaked figure came out of the door of the Carrier.

"Decurion!" Dynamon said sharply into his transmitter, "since when have you had eleven men in your command?"

"Never," came back the prompt answer in Dynamon's ears. As the decurion faced about to count his men, one of them moved over beside Dynamon.

"Forgive me, Dynamon," came a soft feminine voice, "but I had to come with you. It's Keltry. Please don't send me back, I promise not to be any trouble."

Dynamon hesitated, then reluctantly agreed to allow her to come along.

"Stay close to Thamon," he warned, and started off down the valley, the rest of the party following him.

Lightened as they were to keep from sinking deep into the treacherous powdery sand, the humans made fast progress, accelerated by the strong breeze that blew at their backs down the valley. At that, Dynamon realized that the lofty mountains on either side provided protection against immeasurably stronger winds higher up. From the saw-toothed peaks on the left, dark streamers of sand stood out for yards, indicating constant winds of gale proportions up there.

The valley itself, as far as Dynamon could see in the dim half-light, was barren of any kind of life. There was no sign of a creeping, crawling, or flying creature; nor was there any vegetation, trees or grass. Dynamon led his column nearly a mile down the unchanging gray of the valley and then called a halt.

"Thamon," he said, beckoning the scientist to him, "can you see any possibility of human habitation in this valley?"

"Off-hand, I don't, not on the surface," the scientist replied. "I would have to test the atmosphere for oxygen, but I doubt if there is a large enough proportion. My guess is that there is nothing but nitrogen in this air. That won't support human life, or any other kind of life except possibly certain kinds of plants."

"What about tridium?" said Dynamon. "How do you go about looking for it?"

"Electrophysiological tests of all kinds," said Thamon. "I must say this valley doesn't look very encouraging. It looks like burned out volcanic ash. Say! What's that up the valley?"

Dynamon gazed back in the direction of the Cosmos Carrier, and felt an uneasy prickling along his spine. The desert valley floor behind them seemed suddenly to have sprouted some tall bushes. There were possibly a dozen of them standing at intervals of twenty yards. They were too far away—perhaps one eighth of a mile—for Dynamon to see them very well, but they appeared to consist of a score of leafless branches radiating outward in all directions from a small core. It was as if a basket ball was bristling with ten-foot javelins.

"Where did they come from?" Dynamon gasped. "I didn't see them when we walked over that ground a few minutes ago."

"Nor I," agreed Thamon. "I can't imagine where they came from."

Just then one of the bushes apparently moved a few feet as if blown by the wind.

"Good Lord!" exclaimed Thamon. "Did you see that? One of those things rolled forward!"

Then another of the fantastic bushes started to roll, and another, and another. In a moment all twelve of the extraordinary apparitions were rolling rapidly down the wind toward the humans. Dynamon felt the hair on the back of his neck stiffen, and he sprang into action, commanding his soldiers to converge around him.

"Thamon, what are those things!" Dynamon cried.

"I don't know," the scientist replied. "I don't think they can be animals. But they might be rootless nitrogen-feeding plants of some kind. Look! Those branches are covered with long thorns!"

The fantastic creatures were rolling swiftly down on the little group of humans, and Dynamon could see the sharp thorns around the end of each branch. He reached into the box at his hip.

"Decuria, ready with voltage bombs," he commanded, and looking around saw that each man held one of the little glass bombs in his hand. The bushes were only fifty feet away now, rolling lightly over the gray sand on their spindly branches.

"Ready?" warned Dynamon, "throw!"

A shower of glistening glass balls flew through the air into the midst of the menacing apparitions. There was a series of blinding flashes and loud reports. Some jagged white lines appeared among the black branches of the monsters, but they kept right on rolling downwind. Dynamon felt a surge of dismay. Those voltage bombs had been, for years, Man's best weapon.

"They're plants all right!" came Thamon's voice. "You can't kill them with electricity any more than you can kill a tree!"

Dynamon looked at the men huddled about him and thought quickly.

"All we can do, men, is to try and dodge them," he announced. "Spread out and as soon as one of those things passes you run upwind! Keltry! Thamon! Stay close to me."

The line of rolling bushes was almost upon them as the soldiers deployed in all directions. Seizing Keltry by the hand, Dynamon leapt to one side dragging her out of the path of one of the spiney monsters. Thamon gasped a warning, and Dynamon, turning his head, felt a thrill of horror as he saw another of the creatures almost on top of them. Acting instinctively, Dynamon snatched the metal staff from Thamon's hands and flailed frantically at the black, thorny branches. To his amazement, they shivered and snapped under the metal rod like matchwood. Hardly daring to believe his eyes, Dynamon struck again and again at the horrible creature, until in a few minutes it was nothing but a pile of scattered, broken faggots on the gray sand.

But cries for help and screams of anguish sounded in Dynamon's ear phones, and he saw that five of the soldiers were on the ground impaled on the cruel thorns of others of the monsters. He ran toward them and beat them to pieces with the rod but too late to save the lives of the men. They lay pierced in a dozen places by long, black thorns. The rest of the Decuria had managed to dodge the whirling branches of the other bushes and now stood safely up wind of them. Dynamon summoned the survivors around him.

"What do you think, Thamon?" he asked. "In your opinion are there likely to be more of these horrible things around?"

"There may easily be," the scientist replied promptly. "But since the only defense against them is this one metal rod, I recommend that we leave our unfortunate comrades here and head immediately for the mountains over there. Those poor fellows are beyond our help and we should be able to find better protection from these blood-thirsty thorn-bushes among the foot hills. When we get there we can work upwind until we're opposite the Carrier again."

"That sounds like good advice," said Dynamon. "And we'll act on it. It's getting so dark now that we couldn't see to protect ourselves if any more of those creatures came rolling down the wind. Everyone join hands and follow me."

After a nerve-racking march of about twenty-five minutes through the gathering darkness, the party of nine humans felt the ground rising beneath their feet. Dynamon halted and hurled a voltage bomb forward and upward. As the bomb exploded, the momentary flash revealed to the party that they were at the foot of a steep, rock-strewn declivity. Dynamon led the party upward, feeling his way over the great boulders. After a few minutes of climbing, he called another halt and again threw a voltage bomb.

"We'll stay here for a few hours," the centurion announced, "until it gets light enough to see our way. We will be safe in the lee of these big rocks, so make yourselves comfortable."

Nine dim figures spread out on the sloping ground. Then one of them drifted apart from the rest, up hill.

"Who is that?" Dynamon demanded.

"Keltry," came the answer. "I am just going up hill a little distance. When you exploded that last bomb I thought I saw something that looked like the edge of a volcanic crater."

"You can't see anything in this darkness," said Dynamon. "Wait till it gets light again before you do any exploring."

"Oh, I won't go far," said Keltry. "Really, I won't."

"Well, be sure that you don't," Dynamon smiled into his transmitter. Then he said, "Thamon, where are you?"

"Right here," and a figure moved over beside the centurion.

Dynamon's question was casual.

"Did you see anything that looked like a volcanic crater?"

"Come to think of it," the scientist replied, "I think I did. It's just up here a few yards."

"Shall we go along and have a look at it too, then?" said Dynamon, getting up on his feet. Just then, he stood rooted with horror as a piercing scream rang in his ear phone.

"Dynamon! Dynamon, I'm falling!"

"Keltry!" the centurion exclaimed. "What's the matter? Has something happened to your helmet?"

"Yes!" Keltry's voice was fainter. "I've lost it! It was unfastened, and when I stumbled, it rolled off!" Fainter and fainter grew the voice. "I'm falling down a black hole a mile a minute!" With a muttered sob, Dynamon scrambled up the slope. A moment later, his foot stepped out on empty space. He started to fall into nothingness.

"Keltry!" he cried into his transmitter. "Where are you? Answer me!"

Straining his ears Dynamon heard a tiny voice far away saying, "I'm still falling."

"I'm coming after you, Keltry!" the centurion yelled, and reaching up to the knob on his helmet, twisted frantically. By doing that, he multiplied the gravitational pull of the planet and was now falling much more swiftly than Keltry. How deep this black pit was, Dynamon had no idea, but he prayed it would be deep enough so that he could catch up with Keltry before she hit the bottom. It was a desperate chance but Dynamon was willing to take it.

"Keltry!" he shouted into the transmitter. "Can you hear me? I'm coming for you."

"Yes, I hear you, Dynamon," came the answer, and Dynamon's heart leapt as it seemed to him that the voice sounded a little stronger.

"Keep your courage up, Keltry," he said, trying to sound calm. "I'm falling faster than you are. There doesn't seem to be any bottom to this pit so I'm bound to catch up with you."

"Oh, Dynamon! You shouldn't have jumped after me. There's—there's only—one chance in a million that we don't crash."

Keltry was bravely trying to hide the despair and terror in her voice, but most important of all to Dynamon was the fact that she sounded—still nearer! He resolutely put out of his mind the frightful probability that at any second, first Keltry and then he, would be dashed to pieces at the bottom of the pit. It seemed to him that he had been falling for miles, and he thought that there was beginning to be more air resistance now. He bent his head and peered downward, trying to pierce the inky blackness with his eyes, but he could see nothing. It was a fantastic sensation or, better still, a lack of all sensation. He seemed to be resting immobile in a black nothingness, with only the rushing air tearing at his cloak to indicate that he was falling.

"Keep talking, Keltry," he cried.

"Oh, you sound so much nearer!" There was a note of incredulous hope in Keltry's voice.

"I told you I'd catch up with you!" Dynamon exulted.

Suddenly, his heart gave a great bound. He was still peering downward and it seemed to him that far away he could see a tiny pin point of light.

"Keltry!" he cried, "am I seeing things? Or is there something that looks like a star; way down there?"

"Oh, I think I see it!" Keltry answered breathlessly. "Dynamon, what could that mean?"

"I don't know," said Dynamon, "but it seems to be growing larger, and I'm getting much nearer to you."

Under his fascinated eyes, the star grew bigger and brighter by the second. In a few moments Dynamon, hardly daring to believe his eyes, thought he could make out the outlines of a flying figure between him and the light.

"Keltry!" he shouted. "I've almost caught up with you! Hold your hands up over your head."

"Oh Dynamon! I think I can see you."

The point of light which Dynamon thought was a star, was growing into a larger, brighter disk. Keltry's body was sharply outlined against it now, and she seemed to be scarcely ten feet away. Dynamon bent himself into a jack-knife dive and kicked his feet up behind him. The air pressure was tremendous now, and Dynamon began to realize that it was no star, or sun, or planet down below but the bottom of the pit. Rays of light spread upward, illuminating the smooth, shiny sides of the shaft. A few more agonizing seconds went past and Dynamon's hands grazed the tips of Keltry's upraised fingers. Dynamon dared not estimate how far above the bottom of the pit they were, but concentrated on gaining the few inches he needed to get a grip on one of Keltry's wrists.

"We've—almost—made it!" he panted. "Here—grab my right arm and hang on for dear life!"

An involuntary shout of relief came from Dynamon's lips as he felt Keltry's strong fingers close over his arm.

"Hang on!" he shouted, and his left hand flew up to his helmet and carefully turned the counter-gravitation knob. At the same time, he twisted his back around and fought his feet downward. A moment later, he gripped Keltry's torso under the arms with his knees. Frantically, he tried to estimate how far above the bottom of the pit they were. They might be five thousand feet—or five hundred feet. Slowly he turned the dial on his helmet, resisting the almost insuperable impulse to twist the knob too fast. If he tried to stop their fall too quickly it would tear their bodies apart.

Slowly, ever slowly, the air-rush diminished. By now, they were well down into the area illuminated from the bottom of the pit. And they could see that they were falling through a round shaft perhaps one hundred feet in diameter. Dynamon judged that they were less than one hundred feet off the bottom.

"Look out, Keltry," he said. "I've got to put on the brakes hard."

He gritted his teeth, and flicked the knob on his helmet. He stifled a groan as invisible ropes attached to his feet and hands seemed to be trying to pull him apart. But gradually the terrific pressure released. He moved the knob a shade, and released the grip of his knees on Keltry.

"There!" he grunted as they both landed lightly on solid ground. "There wasn't two seconds to spare."

Keltry drew a shuddering sigh and put a hand on Dynamon's arm for support.

"Oh, Dynamon!" she whispered, "if I weren't such a well brought-up girl I would break down and cry from sheer relief."

"I don't blame you," said Dynamon in a voice that shook a little. "That was quite an experience, but we came out of it all right. Now, where do you suppose we are? How do you suppose this pit was ever formed?"

The two Earth-people stared around them curiously. They were bathed in a bright light, and yet there was no apparent source of illumination. It began to dawn on them that the rocks which formed the side walls at the base of the shaft, were themselves luminous, glowing with a curious greenish light. Dynamon tilted his head back and stared up into the darkening shaft. Suddenly, he uttered an exclamation and, seizing Keltry by the wrist dragged her to one side. A few seconds later, a round object dropped out of the shaft and bounced on the ground. It was Keltry's counter-gravity helmet.

Dynamon reached down and picked it up. "It's a good thing that these things are well built," he remarked with a smile, "or this would be smashed to bits. The knob is still set for plus ten pounds, and that was quite a fall. I wonder whether it still works."

He twisted the knob experimentally and the helmet started to sail upward.

"Say!" Dynamon cried. "It works, all right! Here, put it on Keltry."

Keltry accepted the helmet with a laugh, put it on her head and was buckling it under her chin when her blood suddenly congealed in her veins. A loud shout rang echoingly through the shaft. Dynamon whirled around and beheld a curious figure standing in front of a rock not sixty feet away. It stood upright on two legs, and cradled a sort of club in its arms. Its head was covered with long, yellow hair that fell down on to its shoulders, and the lower half of its face was covered with coarse, yellow hair. Blue eyes glinted from under shaggy brows in a menacing glare at the two Earth-people.

"It looks quite human, doesn't it?" whispered Keltry.

Dynamon nodded and slid his ear phone off his right ear as he saw the stranger's hairy mouth opening and closing. Keltry followed his example in time to hear the stranger's rumbling voice.

"Whoo-yoo?"

Dynamon touched Keltry's hand. "That sounded like 'who are you' didn't it?" he said wonderingly.

"It certainly did," Keltry answered. "I think that's some kind of human."

"If it's a human," Dynamon said, "then there must be some sort of breathable atmosphere down here. You notice he's not wearing any oxygen mask."

"Whoo-yoo?" the stranger repeated, "an whey cum fum?"

"He's speaking a kind of English!" said Keltry excitedly. "He said, 'who are you' and 'where do you come from'!"

"By Jupiter!" cried Dynamon. "I think you're right. If he can breathe without a mask, so can we. I'll have a little talk with him."

A moment later the centurion stood bare-headed, helmet and oxygen mask in hand.

"We're humans from Earth," he told the stranger, pronouncing each word carefully. "Who are you?"

The stranger's eyes and mouth flew open in astonishment and the rod sagged in his hands.

"Humes! Fum Earth!" he cried hoarsely, then turned his head, and gave an ear-splitting yell.

A moment later, a dozen or more short, hairy-faced creatures closely resembling the first stranger came tumbling through a passageway behind him and stood rooted with astonishment at the sight of Dynamon and Keltry. Their bodies were completely covered, the torsoes, with loose, gray tunics, and the legs with ugly, baggy tubes. They advanced cautiously on the two people from Earth.

"Take off your helmet and mask," Dynamon directed Keltry, "the air is perfectly good. We'll try and find out the mystery of how these humans ever got here."

He turned and addressed the first stranger, again enunciating slowly and carefully. Immediately the whole crowd burst into excited jabbering. Here and there Dynamon thought he recognized a word. Finally, one man taller than the rest stepped forward.

"Yoo cum thus," he declared.

"Certainly," Dynamon nodded with a smile, and reached out a hand to Keltry. The crowd, with wondering eyes, opened up a line and the two young people from Earth followed their self-appointed guide through it. A short narrow passageway led off at a sharp angle through the rocky wall of the pit, and presently Dynamon and Keltry found themselves on what appeared to be a hill top. Both of them gave little gasps as a vast and magnificent panorama spread out before their astonished eyes. It was as if they had stepped into a new world.

A gently undulating plain stretched away in three directions as far as their eyes could see. It was predominantly gray in color, but here and there, were scattered long, narrow strips of green. These green strips all had shimmering, silvery borders, and Dynamon couldn't help recalling to mind some arid spots back on the Earth that were criss-crossed with irrigation ditches. There were no trees on this vast plain, but strewn around in a haphazard way, were a quantity of great boulders. And these rocks, like the rocks at the base of the pit, glowed luminously. However, the landscape was clearly illuminated by some other source than those scattered rocks. Dynamon lifted his eyes upward and saw that above them, and stretching as far as the eye could reach, there was a softly luminous ceiling. There was no way of telling how high up this ceiling was. It might be twenty feet or twenty miles. The effect was like that of certain days on the Earth, when wide-spread clouds blanket the sky and diffuse the sun's rays.

The plain was by no means deserted. Here and there along the green strips four-legged creatures moved slowly, creatures that, on Earth Dynamon would have said were cows. Nearer at hand, a flock of small white creatures milled around aimlessly, and Dynamon could have sworn he heard the cackle of hens. Dynamon glanced over his shoulder and saw that the little hairy-faced men were filing out of the passageway to the pit. The guide tugged at his sleeve.

"This oo-ay," he said and pointed to his right.

Still holding Keltry's hand, Dynamon turned and followed the man, and the others fell in behind them. Their way eventually led toward a tall set of cliffs at the base of which a score or so of cave-like openings could be seen.

"These are humans, aren't they, Dynamon?" Keltry whispered.

"They certainly look like it," Dynamon answered, "although obviously they're very primitive."

"Then how and when did they come to Saturn?" Keltry persisted.

"I haven't the faintest idea," Dynamon shrugged. "Perhaps we'll find out."

Other strange humans came running up the hill and joined the crowd behind them. Apparently they were not all men, for some of them had no hair on their faces and wore long robes over their bodies. The guide led them straight to one of the openings in the cliff, then halted and faced the two adventurers impressively.

"The koo-een!" he announced in a loud tone.

Dynamon and Keltry looked wonderingly at each other and then back to the guide. At that moment a woman appeared at the mouth of the cave. She was small and delicately formed and strikingly beautiful. She had the bluest of eyes and golden hair that fell away on either side of a marble brow. A long-sleeved white garment gathered at the waist covered her from neck to toe, but its shapeless folds could scarcely conceal the delicious curves of her little body.

"Humes!" the guide shouted proudly, "fum Earth!"

The woman's blue eyes widened as she stared solemnly at Dynamon and Keltry.

"Are you from Earth?" she said in slow musical tones. "So strange! So wonderful! How did you come?"

Dynamon grinned. "We came in a Cosmos Carrier," he said easily. "And to us, it seems even more strange and more wonderful that we find humans already on Saturn."

A shy answering smile came over the woman's beautiful face.

"We have been here hundreds of years," she replied in the same slow accents. "But come inside the Palace and we will talk."

She turned with an inviting look and the two adventurers from Earth followed her through a passageway lined with the, by now, familiar luminous rocks. They came out in a fairly large, high-ceilinged room, in the center of which was a sort of table made out of a long, trimmed slab of rock. At one end of this table was a high-back chair made of woven reeds. The woman walked over to the chair and sitting down in it, indicated stools on either side of her.

"Sit down," she said, "and tell me more about yourselves."

"Thank you," Dynamon answered, and turning to his companion said, "It's warm in here, I think we might take off these cloaks."

Keltry nodded, and putting her hand to the throat fastening, zipped it downward. Dynamon did likewise and the two stepped out of their cloaks. There was a sudden scream from the beautiful little woman, and her hands flew up in front of her eyes.

"What are you doing?" she squealed. "Why you're—you're practically naked! You're positively immodest!"

Keltry threw a startled glance at Dynamon's long, brown legs.

"Why, not at all," she said quietly. "We are dressed like everyone else on Earth at the present time. Modesty with us, nowadays, is something much more important than lengths of cloth."

The little woman kept her hands before her eyes and shook her head vigorously. "It's immodest," she insisted, "and you must put on your clothes at once. Don't you realize that I'm the queen?"

Reluctantly, Keltry and Dynamon stepped back into their heavy cloaks and zipped them up the front.

"Well! that's better," said the little queen primly. "My goodness," she said with a slight glance, "is everybody on Earth as big and brown as you two?"

"We're about average, I should say," Keltry answered with a smile. "And seriously, we didn't mean to offend you in the matter of clothes."

"Well we, on Saturn," said the little queen, "don't believe in indecent exposure. Now, you say you came in some kind of a carrier?"

"Yes," said Dynamon. "It's up on the surface. We were exploring in the darkness and fell down the long shaft."

"Why weren't you killed?" said the queen, blue eyes wide. Dynamon explained the counter-gravity helmets. It took considerable explanation, because the queen was inclined to disbelieve the whole story. She finally accepted it, however, and then launched into a long series of questions about the Cosmos Carrier and about the state of the Earth. Eventually Dynamon found an opening and started asking questions on his part.

"We're anxious to know about you and your people on Saturn," he suggested. "Have you a name or are you addressed only as Queen?"

"I am Queen Diana," the little woman stated. "The last of my line. I am a Bolton, and the Boltons have been rulers of Saturn ever since we came here."

"Bolton!" Dynamon shouted. "Are you a descendant of Leonard Bolton?"

"Yes!" replied the queen, with a delighted smile. "Do they still remember Leonard Bolton on Earth?"

"We know that he designed a contrivance called a 'space ship', but that's all. Did he actually build such a ship, and is that how you come to be here so many thousands of miles from Earth?"

"Yes," said Queen Diana, proudly. "It's all down in some books which I will show you. Leonard Bolton built a space ship which was big enough to hold ten families and their belongings. There was a terrible war going on and he thought the only place to find safety was another planet. So the 'space ship' left the Earth by means of a thing called a 'rocket,' whatever that is. And they wandered around for years in space till they finally came into Saturn's orbit, and the tremendous gravity pulled the ship right through the light outer crust into this Nether World. I don't know how many years ago that was, but we have been here ever since."

"Well that is an amazing story," said Dynamon. "And I would like to see those books you mentioned. How incredibly fortunate that the 'space ship' broke through into this Nether World, where there is an atmosphere that will support life. And it is pretty miraculous too, that the 'space ship' didn't break up from the force of hitting the outer crust."

"Well, the books say that it was broken up somewhat," the queen answered, "but nobody was hurt. And after they unloaded the ship, they took it apart so that they could use the metal in it for other things."

She was eyeing him admiringly.

"And the colony has survived over a thousand years," Dynamon mused. He could not help thinking how, in comparison with the people on Earth, the survivors of Bolton's expedition were a rather poor lot. They had made no progress at all in the thousand years, mentally or culturally; from all evidences they had, on the contrary, retrogressed at least to a degree. Then across his mind flitted a picture of the hardships these brave souls had to endure in establishing themselves on the new planet. At no time could they have even hoped to return to Earth.

With their limited equipment they had set out to make the most of their new world. The great caves offered natural shelter so it was small wonder that they made their homes in them.

Dynamon, although a soldier to his finger tips, had none of the haughtiness and cruelty which are so often found in the warriors of today. Quickly his pity for the colonists turned into admiration, and he turned gently to face Queen Diana again.

"Tell me," he asked, "Are we the first strangers you have seen? You haven't, by any chance, been visited by Martians, have you?"

"Martians," said the queen. "What are they?"

"At present, they are just about the worst enemies of human beings," Dynamon replied tersely.

"No," said the queen, "our only enemies here are the land-krakens. We have been fighting them for hundreds of years and we have never been able to exterminate them, because they're so hard to kill."

"Land-krakens," said Dynamon. "What sort of creature are they?"

"They are great, crawling monsters," the queen told him. "They have a dozen long, flexible arms that curl around their victims and strangle them. They lie in wait for our cows and kill them easily, and now and then, they catch a human being. They're terribly hard to kill even with bullets—they seem to be made of gristle and jelly."

Just as the queen spoke, there was a chorus of shouts outside the cave, followed by three or four sharp reports, in rapid succession. The queen stood up quickly, as one of her subjects rushed into the cave.

"Land-kraken!" he shouted. "Ter'ble biggun!"

Without a word, the queen picked up her long skirts and ran to the entrance of the cave, Dynamon and Keltry following close behind. An extraordinary sight met their eyes.

At the fool of the little hill, fifty or sixty shouting men were ringed around a horrible mass of thrashing, gray tentacles. Several of the men were pointing their black rods at the beast.

"Oh, it is a big one," the queen cried. "Our guns will be useless against that thick hide—the bullets will just skim off."

There were several more reports and smoke curled from the ends of the rods. Several long, grey tentacles rose up above the mass, and the crowd surged backward in all directions. Suddenly one of the slimy arms streaked downward and outward, and a moment later a struggling, screaming human was lifted high in the air. A thrill of horror went through Dynamon, and Keltry clutched his arm.

"Their ancient fire-arms are useless," she said in a tense whisper. "Perhaps a voltage bomb—"

But Dynamon was already running down the slope, fumbling at the black box at his hip. The concerted groan of despair from the crowd suddenly changed to a shout as the unfortunate human somehow tore loose from the encircling tentacle and dropped to the ground. Just as the land-kraken was reaching for the doomed man with another long arm, Dynamon hurled a voltage bomb over the heads of the crowd. The little glass ball landed squarely in the middle of the writhing gray mass. There was a blinding flash and a loud report. A convulsive shudder rippled over the gray monster and its twelve tentacles suddenly went limp. The crowd looked at it in stunned silence for a second, and then raised a yell of triumph. A noisy mob of little bearded men escorted Dynamon back up the hill to where the beautiful little queen stood, waiting, her blue eyes shining.

"How marvelous! How heroic!" she breathed, as Dynamon came up to her. "You killed the kraken with one blow. How did you do it?"

"Well, you see, Queen Diana," Dynamon replied, patting the black box, "these little voltage bombs have long ago entirely replaced fire-arms on Earth. Their range is shorter but they are far more deadly."

"Oh! So wonderful!" the queen gasped. "I am so glad you came. You shall marry me and I'll make you King of Saturn."

"I am most honored and flattered by your proposal, Queen Diana," Dynamon smiled, "but I am afraid that isn't possible. Keltry and I must go back up the shaft and rejoin our expedition."

"Oh, but you can't!" said the queen suddenly. "Send the girl away if you want"—she waved a careless hand at Keltry-"but you must stay here with me forever."

Dynamon saw Keltry's startled eyes on him and he felt an acute embarrassment. It was an impossible situation. He could not repress a little glow within him from the frank approval of the beautiful, imperious little queen. But at the same time, he knew that he must soon devise some means of making a graceful exit from her presence. His thoughts were interrupted by a sudden cry from the edge of the surrounding crowd. He turned his head and looked along the base of the cliff. A column of cloaked figures, helmeted and masked, were streaming out of the passageway to the pit.

"It's a search party coming after us!" cried Keltry.

They were twenty or so of the soldiers from Earth, and they covered the distance toward Dynamon and Keltry in a short time and forced their way through the crowd of bearded Saturnians. The one in the lead unfastened his oxygen mask and revealed the spectacled face of Thamon.

"Thank goodness, you're alive!" said the scientist fervently. "We never expected to find you. What a fantastic place this is!"

"You are in the kingdom of the Boltons," said Dynamon, "and this is Queen Diana."

The man behind Thamon unmasked, revealing the lean, dark features of Mortoch.

"Congratulations, Dynamon," said the Chief Decurion, dryly, as he in turn was presented to the wide-eyed little queen. "You certainly picked a sort of paradise to fall into. A paradise, I might add, presided over by an angel."

A coy smile crept over the queen's face, then died away at Mortoch's next words.

"I bring you grave news, Dynamon," the Chief Decurion said. "There are two Martian Carriers in the vicinity. We haven't seen them yet, but we intercepted a long-wave conversation between them. What do you intend to do about it?"

"Why, I think we should go right back to the surface," Dynamon replied. "Could you tell from their conversation whether they knew that we were on Saturn?"

"Apparently they knew we were somewhere around," said Mortoch, "but hadn't located us yet."

"Well, we'd better hurry right on up then," said Dynamon, "so that we can get back to our Carrier before they find it."

"Oh, but you can't go!" said the little queen in a shrill voice, "I forbid it."

"I wish we could stay, Queen Diana," Dynamon answered, "but there's dangerous work to be done up on the surface."

"But why go to the surface at all?" the queen demanded. "Why not stay down here and keep away from the danger?"

"No, Queen Diana," Dynamon said, keenly conscious of Mortoch's lurking smile. "Duty calls and we must go. Perhaps when we have finished our work we will pay you another visit. All right, men, here we go."

The centurion, Keltry by his side, led the way back to the entrance to the pit, while the Saturnians, grouped around their little queen, gaped after them. As the little force stood in the bottom of the pit adjusting their helmets and oxygen masks preparatory to ascending to the surface, Mortoch leaned over to Dynamon.

"That wasn't such a bad idea of the beautiful Diana's," he murmured. "Personally, I wouldn't mind spending a few safe years down there with her. It would be better than facing those deadly Photo-Atomic Rays of the Martians."

"If it's safety you're interested in, Mortoch," said Dynamon, dryly, "we'll try and get you, as soon as possible, to the safety of the Carrier. Anyway, perhaps the Martians are just exploring and didn't come equipped with the Ray."

But as the centurion turned the knob in his helmet and shot up through the great shaft, he felt in his heart no great hope that such, indeed, would be the case. If the Martian Carrier were in the vicinity of Saturn it was altogether likely that they had come prepared to destroy the Earth Carrier, and would be equipped with their best weapon. Dynamon hoped against hope that he and the little force would reach the surface in time to get to their own Carrier, whose thick walls the Martians' Ray could not penetrate. After that, it would be a case of maneuvering the Carrier in such a way as to try to disable the Martians' ships.

The humans, their gravity repellors turned up full strength, whizzed up the black shaft at a tremendous rate of speed. Even so, it seemed hours before a small gray disc above him warned Dynamon that they were nearing the top. He spoke some words of command into his radio phone and cut down his upward speed. In a few moments he stepped over the rim of the shaft into the gray light of the Saturnian midday. He glanced down into the valley in the direction of the Carrier and felt a shock of dismay go through him.

The gray Earth Carrier was in the same place, but a half a mile on either side of it were two flaming red Martian Carriers. And out on the gray sand far from any of the ships a furious battle was going on. Some twenty tall, human figures were ringed around by a swarm of tiny, globular Martians. A continuous series of white flashes showed that the humans were desperately hurling their voltage bombs, but the encircling Martians were keeping well out of range and a dozen still forms on the ground showed that the invisible Photo-Atomic Ray was doing its deadly work.

All too clearly, Dynamon saw what had happened. In the absence of a commanding officer, himself or Mortoch, Borion had unwarily sent a force of soldiers out scouting. The Martians had swooped down, landed swiftly, and cut off the force from the Carrier. The humans were desperately trying to cut through to safety, but their situation looked hopeless.

Quickly, Dynamon turned and faced the men behind him and held up his hands in a gesture signifying that no one should use his radio phone. He had determined to try and help his beleaguered soldiers down in the valley, and the only way that could successfully be done was to surprise-attack swiftly on the rear of the Martians. He motioned Keltry and Thamon back into the pit and then, sweeping his arm forward in a wide arc, he plunged down the hillside. But before he had covered half the distance to the combat in the valley, Dynamon realized that his attack was coming too late. The Photo-Atomic Ray was cutting down the little force of humans like an invisible scythe. There were only nine of them left now and one by one these were falling. A thousand thoughts raced through Dynamon's head. Should he go ahead with the attack, courting on getting within bombing distance of the Martians unnoticed, before they could swing their Photo-Atomic Ray around? Or, should he change direction, skirting the enemy, and make a run for the Carrier? Suddenly, his blood froze in his veins as a voice sounded in his ear phones.

"This is suicide, Dynamon!" It was Mortoch's voice.

"It's suicide now!" said Dynamon through clenched teeth. "You fool! You have given us away!"

There was an instant reaction from the swarming Martians in the valley. A large group of them broke away from the combat and rolled over the gray sand toward Dynamon's detachment. The centurion halted his men abruptly. It was sure annihilation to try and stand in the face of the oncoming men of Mars.

"Back to the pit!" Dynamon commanded. "It's our only chance. Once we get down there we'll decide what to do later."

The little force just barely made it to the mouth of the shaft. The Martians were coming up rapidly behind them, and Dynamon could see the big, black cones which produced the invisible Ray.

The descent down the shaft was rapid, Dynamon being the last to land on the shiny floor. Immediately, he marched his men through the passageway into the Nether World and detailed two men to remain and guard the entrance to the pit.

"I don't believe the Martians will follow us down," he said. "If they do, we can easily defend the passageway."

Then he turned and singled out the Chief Decurion.

"Mortoch," he announced, "you are under arrest. You disobeyed my orders in regard to using the radio phone, and by doing so you betrayed our presence to the enemy. I will dispose of your case later."

Mortoch stepped forward, a sardonic gleam in his dark eyes.

"And suppose I refuse to be arrested?" he said. "If I had not disobeyed the order, you would have led us into certain death." Mortoch swept the crowd of soldiers with a burning look. "Men, I proclaim that Dynamon is incompetent to command you. Henceforth, you will take your orders from me—and you, Dynamon, are the one who is under arrest."

"Mortoch!" Dynamon cried. "You are out of your mind!"

"Not at all," Mortoch returned. "I am merely assuming the command which should have been mine to begin with. Put your hands up in the air, Dynamon, and backward march till I tell you to stop. And let nobody else make a move"—Mortoch's rasping voice rose to a shout—"I have in each hand a voltage bomb which I shall not hesitate to throw if anybody attempts to cross my will."

"This is madness!" Dynamon cried hoarsely. "You can't hope to get away with this!" He strode forward angrily.

"Back!" roared Mortoch, and raised his right hand threateningly.

Dynamon staggered back in bewilderment from the soldiers who stood in silence, too shocked to make a move. Helpless against the voltage bombs in Mortoch's hands, the centurion stepped slowly backward, arms upraised. It was an impossible situation, and for the moment, Dynamon felt powerless to do anything about it. He reproached himself bitterly for not being more wary of Mortoch. Up till now he had been conscious of the Chief Ducurion's enmity, but he had never thought that the man would erupt into open mutiny.

Dynamon threw a swift glance over his shoulder and saw that he was only two paces away from one of those curious, luminous rocks. It was approximately cylindrical in shape, six feet wide and perhaps twenty feet tall. Dynamon took another step backward and turned his head to face Mortoch. His back was almost touching the rock now, and a desperate plan formed in his head. That was to make a sudden leap around the rock. Once behind it and protected by its mass, he would have time to pull out one of his own voltage bombs and await Mortoch's next move.

But Dynamon had not truly measured the state of Mortoch's mind. There was a sudden scream from Keltry as Mortoch, with a lightning movement, drew back his right arm and flung the voltage bomb straight at Dynamon's chest. The little glass ball sped unerringly across the intervening twenty feet. There was no time to dodge. Dynamon pressed his back against the rock and closed his eyes. It was the end.

Dynamon felt the little bomb bump his chest. But—wonder of wonders! There was no blinding flash—no explosion. There was just a silvery tinkle as the glass ball shattered at his feet. Dynamon opened his eyes and found that he was still alive. An incredulous shout went up from the horrified crowd and Thamon started running toward him.

"Tridium!" shouted the scientist. "You have discovered tridium!"

As in a dream, Dynamon saw the soldiers overpowering Mortoch and heard himself say, "What do you mean? Where is the tridium?" He stared about in wonder.

"The rock!" cried Thamon excitedly. "You touched the rock and were instantly insulated against the electric charge. Great heavens! What a discovery! Every one of these luminous rocks must be made of tridium."

Dynamon turned around and placed a hand on the glowing rock. Instantly, he felt himself enveloped in an extraordinary transparent aura.

"You see!" cried Thamon, and struck at the rock with his metal rod. Evidently, it was almost as soft as chalk, for several pieces as big as a man's fist chipped off and fell to the ground. Thamon stooped down and picked one of the pieces up and immediately he, too, stood in a curious, gleaming aura.

"It's tridium, all right!" exclaimed the scientist. "There can be no doubt about it. We knew it was on Saturn and we knew what its properties were, but we didn't know what it looked like. Do you realize what this means, Dynamon? It means that we may finally have found the defense against the Photo-Atomic Ray!"

Dynamon felt a little dizzy. Not only had he been snatched from what appeared to be certain death but he had inadvertently made a discovery that might save the people of the world from conquest at the hands of the Martians.

"Thamon, are you quite sure?" he said. "Are you quite sure that this will work against the Ray?"

"No," replied Thamon promptly. "I won't be quite sure until we've tested it out. From a theoretical standpoint, this glowing cloud, this aura that surrounds us as we touch a piece of tridium should insulate us against the Ray. But to be absolutely certain, somebody will have to expose himself to the Ray. Someone among us must go up to the surface holding a piece of tridium in his hand and face the Martians. If he is killed, then I'm wrong. But if he is not killed, then the Martians are at our mercy. We can walk up to them untouched and crush their egg-shell skulls with our bare fists."

"I see," said Dynamon gravely. "Then, one of us must be a heroic experimental guinea pig?"

"Exactly," said Thamon.

Dynamon looked over the silent group of soldiers, at Mortoch, shoulders hunched in the grip of two stalwarts. Then he bowed his head in thought for a moment.

"Men," he said, finally, "this is not a case of calling for volunteers. I think any one of us is brave enough to offer his life for the good of the rest of the human beings, but I think we should decide who is to do this dirty work by drawing lots."

"No!"

It was Mortoch. In his eyes was a wild, hunted look, and his voice was hoarse, but there was deep sincerity in his tones.

"Dynamon," said the Chief Decurion, "I went off my head with jealousy a minute ago. The madness is gone now, and I would give anything if I could undo what I did. You must give me the chance to redeem myself. If I am killed, so much the better for me. And if I am not, so much the better for all the human beings in the world."

Dynamon looked long and searchingly at the Decurion. Finally he said, "Mortoch, I cannot deny your appeal. Take this piece of tridium and go up the shaft. We will be close behind you to observe the experiment."

Just then, there was a shout from the two soldiers who were guarding the passageway to the pit.

"Martians!" they cried. "They are coming down on us! The shaft is full of them!"

Dynamon walked straight toward Mortoch and placed the piece of tridium in his hand.

"Your ordeal is at hand," he said simply, as, in a flash, the bright aura transferred itself to the person of Mortoch.

The two soldiers guarding the entrance to the pit were backing away to either side and throwing voltage bombs into the passageway as Mortoch ran toward them.

"Stop!" he shouted, never slackening his pace. "This is my job! Get out of range!"

He halted six feet away from the mouth of the passage and raised his arms up in a gesture of defiance. An admiring gasp went up from the crowd of watching humans at the tall, lean figure bathed in its luminous glow. Then a deathly silence shut down abruptly as four little figures erupted through the passageway. Martians!

They were scarcely two feet tall, with spindly little bodies and legs, but their heads were more than twice the size of human heads and looked doubly grotesque in their combination helmet-masks. One of them was holding a big, black cone—the Photo-Atomic generator. Quickly the little creature leveled it at Mortoch and pulled a lever on the side. An ominous high-pitched hum filled the air and everyone knew that the death Ray was being poured in all its deadly violence on Mortoch.

Thamon was the first to raise his voice in a shout as Mortoch, unharmed, strode forward and felled the Martian with one blow of his fist. The air rang with human cheers as Mortoch seized two more scurrying Martians by the legs and dashed their brains out on the ground.

"It works!" Thamon yelled, hysterically. "It's tridium! We're saved!"

The scientist was hacking crazily at the rock with his metal staff and jubilant soldiers swarmed around him, picking up pieces of tridium. In a few moments the whole force, every man surrounded by the luminous aura, was bolting through the passageway into the bottom of the pit.

For a short time the Martians tried to put up a battle. But with their chief weapon nullified, they were slaughtered by the dozen, and the survivors began flitting up the shaft. In the midst of the turmoil, Dynamon kept his wits about him. He knew that in order to realize the full value of the tridium discovery, the Martians on the surface must be kept from learning about it. He raised his voice in a mighty shout over the clamor.

"Masks on! Up the shaft at full speed! We must not allow a single Martian to reach the surface!"

Swiftly the Earth-soldiers fastened their masks and took off straight upward. Each one of them clung to their precious lumps of tridium, and in a short time the dark shaft presented an extraordinary spectacle. Each of the twenty-odd humans was bathed in his own ghostly envelope of light, and the fleeing Martians, looking downward, must have felt as if they were being pursued by a squadron of giant fireflies.

The survivors of the massacre below had a head start of their pursuers, but being so much lighter in weight, their gravity-repellors could not push them up through the atmosphere as fast as the humans could go. Gradually they were overtaken and destroyed by Dynamon's force—the last Martian being caught just at the upper mouth of the pit.

Dynamon quickly gathered his men about him while he took stock of the situation in the valley. The three Carriers were in the same position as they were before, but there were no Earth-soldiers left standing. A little circle of fallen bodies offered mute testimony to the hopeless battle put up by the force of three decuria which had made that ill-fated sortie from the Carrier. Now, the Martians from both of the red ships—excluding, of course, the group that had been cut to pieces in the pit—were gathered in a body near the Earth Carrier. Dynamon guessed that they were waiting to see what the Earth people were going to do next. They would soon find out, the centurion thought grimly. Even though there were probably close to two hundred of the evil little creatures down there, they would be no match for the brawny humans insulated against the Photo-Atomic Ray.

Swiftly, Dynamon formulated a plan of action. His first consideration was to try and seize both Martian Carriers. If possible, they must be prevented from leaving the ground and carrying back to Mars the warning that, at last, the humans had found a defense against the Ray. With that in mind, the centurion divided his little force in two. One decuria with its decurion he put under Mortoch, and the other, he commanded himself. Each group was to strike boldly at one of the Martian ships, Mortoch, the nearer one; himself, the farther one.

Dynamon issued his commands by signs, hoping to remain unnoticed by the enemy if he refrained from using the radio-phone. But as he led his group off along the hillside, a sudden activity among the Martians in the valley told him that he had been sighted. They came streaming across the valley floor toward the heights on a shallow crescent, each wing spreading to perform an enveloping movement.

What an unpleasant surprise the nasty little devils are going to get, thought Dynamon, and he switched on his radio-phone. "Follow me, now, on the dead run!"

He dug his toes into the yielding gray sand and ran along the hillside, bending low into the wind. It was heavy going, but the humans were able to make faster progress than their enemies because of their greater weight. Dynamon saw that he and his group were outrunning the Martians and would probably reach their objective sooner. Two thoughts arose in his mind to worry him. One was, that the Martians inside the red ships might lock their doors and take off before he and Mortoch, respectively, could reach them. The other was the fear that Borion, inside the Earth-Carrier, not knowing of the new defense against the Ray, would sally out in a desperate attempt to save—as he might think—the two isolated detachments of humans.

However, Dynamon reflected, those were eventualities over which he had no control. All he could do under the circumstances was pray for good luck.

A glance down into the valley told him that he and his little force were abreast of the Earth-Carrier by now, with a half a mile still to go to reach the Martian ship. The Martians, running parallel, were falling behind a little. Rapping out a command into his transmitter, Dynamon changed his direction slightly, and swung downhill on a direct line with the red ship. At the same time, he and his men readjusted their gravity-control so that their speed was almost doubled. Away to their left, the Martian horde was dropping behind. Dynamon gave an involuntary shout of triumph. He and his party was going to win the race.

As the little knot of speeding humans approached within a hundred yards of the Martian Carrier, another cheer broke from Dynamon's lips. The door at the side of the Carrier swung open and a score of little creatures carrying the once-dreaded black cones tumbled out. The Martians inside the ship, far from running away, were coming out to fight—mistakingly confident that the twelve humans were at their mercy!

Quickly, Dynamon issued orders that two of his men should immediately penetrate the inside of the Carrier and seize the control-room, while the rest stayed outside and engaged the Martian warriors. Then, panting for breath, but none the less confident, the decuria closed in on the Martians.

They were within twenty-five yards of the dwarf-like little creatures before the Martians discovered that something was amiss with the Photo-Atomic Ray. The ugly little men hesitated in momentary dismay, and then started to make a dash for the inside of the Carrier. But by that time, it was too late.

The twelve humans, clothed in their life-preserving auras, swept down on the Martians like avenging angels. All the pent-up hatred against this diabolically cruel enemy now found release. At last, the Martian superiority in weapons was broken. Dynamon and his men waded implacably into the terrified little ogres and slew them without mercy. The whole business was over in less than two minutes.

Without the loss of a man, Dynamon had annihilated the defenders of the Carrier, and two of his soldiers were inside in possession of the control-room. There remained now the job of handling the hundred or so Martians who were moving over the gray sand toward his victorious decuria.

But this force of the enemy had realized that something was radically wrong. They were no longer running, but, in fact, were slowing up to a halt about fifty yards away. Dynamon swung an arm and began to walk toward them. The black cones came up, pointing, all along the long line of Martians. Dynamon's men fanned out on either side of him, walking forward slowly, inexorably.

The line of Martians wavered uncertainly, and then began to fall back in terrified confusion, as the humans remained unharmed by the Ray. Dynamon's voice crackled in nine sets of ear-phones, and the decuria lunged forward. In a moment, they were in the midst of a panic-stricken mass of scurrying Martians. Again, the soldiers from Earth slew pitilessly, until in a short while, fifty-odd of the harried little creatures lay dead. The rest were scattered in headlong flight over the valley.

The business was accomplished none too soon. The thing which Dynamon had feared might happen earlier, happened now. A force of humans, unprotected by tridium, emerged from the big gray Carrier and hastened toward Dynamon. A few minutes earlier and these men would have been mowed down by the Ray. The centurion sighed with relief and ordered the newcomers back to the Cosmos Carrier.

The danger was over.

Twenty minutes later, Dynamon had joined forces again with Mortoch's detachment and was marching back to the mouth of the pit, where Keltry and Thamon were waiting. The past hour had seen a complete and sweeping triumph for the humans. Mortoch's attack on the other Martian ship had been as successful as Dynamon's. Now, both of the Martian Carriers were captured, and their crews and warriors cut to pieces. And, all this had been accomplished with the loss of but one man. One of Mortoch's soldiers had fallen and dropped his lump of tridium. The man had instantly died under the Photo-Atomic Ray.

There remained only one more piece of business to conclude successfully the expedition to Saturn, and Dynamon set about it promptly. Once again he led the way down the pit to the Nether World.

There was great excitement at the bottom of the shaft. The Saturnians were disposing of the bodies of the Martians who had fallen in the first onslaught when Mortoch had proven the efficacy of tridium. And, as Dynamon landed among them, closely followed by Thamon, Keltry and the soldiers, the Saturnians crowded around in a condition bordering on hysteria. They had never before seen Martians, or even dreamed of their existence, so it was not to be wondered at that the primitive humans of the Nether World were excited when the sudden, fierce combat broke out almost in their midst. With the greatest difficulty, Dynamon quieted them down enough so that they heard and complied with his request to be taken to their Queen.

"Queen Diana," he said directly, "in your kingdom, you have any quantity—thousands of tons—of this luminous rock which we have identified as tridium. This substance is the one thing which can save the people of the Earth from the death-ray of the Martians. Will you give me your permission to carry away some of these rocks back to Earth, so that our armies can defend themselves against our enemies?"

The little Queen gave Dynamon a long languorous look.

"If you stay here and be my King," she answered, at length, "I will permit your people to carry away as many of the rocks as they want."

Dynamon's heart sank. He had hoped that Queen Diana had got over that idea. What was he going to do?

"Well, Queen Diana," he said, slowly, trying frantically to think of some way out, "I can't tell you how flattered I am at your proposal, but I don't see how I can accept it."

"Why not?" the queen demanded, imperiously.

Dynamon shook his head helplessly. He was trying to think of some tactful way of telling this spoiled little woman that his heart already belonged to Keltry.

"Well, perhaps you have noticed," he began, "that someone else on this expedition has a—a claim—er—"

"Who do you mean?" the Queen interrupted, "The tall, dark man? The one called Mortoch?"

"Mortoch?" said Dynamon wonderingly.

"Yes, isn't that what you're trying to tell me? Mortoch! That's very interesting," said the Queen dreamily, "Come to think of it, I had noticed that he looked at me very intensely."

A great light dawned on Dynamon. The Queen was jumping to a quite different set of conclusions. He had tried to tell her that he was in love with Keltry, and she thought he was telling her that Mortoch was in love with her, the Queen!

"I think that is very generous of you, Dynamon," said the Queen with a brilliant smile. "You are standing aside in favor of Mortoch because in your eyes, his bravery in facing the Martians gives him a greater claim on my hand."

Dynamon nodded wisely.

"He is a very handsome man," the Queen went on, looking off into space, "perhaps you're right."

"He is just outside," said Dynamon rising. "Let me bring him in to you."

Before the little Queen could say anything more, Dynamon walked briskly out to the mouth of the cave and hailed Mortoch.

"I remember hearing you say," he said, as the Chief Decurion came up to him, "that you wouldn't mind staying here with Queen Diana. Well, it seems that you are to have your wish. The Queen is determined to marry one of us, and right at this moment, she is inclining toward you as a husband. I think it's a fine idea."

Mortoch turned startled eyes on the centurion. Then he began to grin.

"Is that a command?" he asked.

"It is," Dynamon replied.

"I could do lots worse," said Mortoch, "although I'm liable to get homesick now and then."

"Don't forget," said Dynamon, "you'll be King of Saturn, or at least, of this part of Saturn. Go on inside, now, she's waiting for you."

Not long afterwards, Queen Diana, her eyes shining, appeared at the entrance to her cave. Her hand rested lightly on Mortoch's arm, and she announced to her people that at last she was taking a husband and giving the Nether World of Saturn, a King. As cheer after cheer went up from the bearded Saturnians, Dynamon bent over the Queen's hand and kissed it. He, then, received gracious permission to take away as much tridium as he needed.

Keltry stood between Dynamon and Thamon and the three of them stared into the bow periscope screens in the control-room of the Carrier. Borion came over and joined them.

"Well, there she is," said the navigator, fondly. "There was a time back there on Saturn when I kind of doubted that any of us would ever see her again."

The chief image in the screens was a glowing sphere about the size of a man's head. It was Earth. Already, the watchers in the control-room could make out the outlines of the continents.

"But at that, I guess we got off lightly," continued Borion, "We lost thirty-nine men—including Mortoch—but just think what we're bringing back! We've got enough tridium in these three Carriers to divide up among ten thousand men. I was afraid we might have trouble with so much of the stuff—afraid it might affect the magnets."

"No, it's a curiously inert substance," said Thamon, "I suppose that's why it can absorb the terrific shock of the Photo-Atomic Ray so easily. What's the news from Headquarters, Dynamon?"

"It's pretty sketchy," said the centurion, "Argallum was afraid to say too much for fear the Martians might be able to decode the message. But it looks as if we are going to be just about in the nick of time. The Martian invasion began ten months ago, just about the time we were leaving Saturn. Even though they came without warning in thousands of ships, our people managed to beat them off for quite a while. Some cities were destroyed, but Copia wasn't touched—too well guarded. But then, even though our people maintained, and still do maintain, superiority in the air, those Martian devils found some remote desert spot unguarded and landed thousands of their men. They were all equipped with the Ray, of course, and our land forces simply couldn't stand up against them. They've been driving steadily ever since, and right now, they're within seventy miles of Copia."

"Whew!" gasped Borion.

"I should say we are in the nick of time," said Keltry.

"Heavens!" exclaimed Thamon, "I shudder to think what would happen to the World right now, Keltry, if you hadn't fallen down that pit!"

"That's right," laughed Dynamon.

Just then, a communications man walked into the control-room and handed Dynamon a message.

He read it avidly.

"That's good news," the centurion remarked, looking up from the piece of paper, "Argallum is sending a heavy convoy to meet us. How soon will we be landing, Borion?"

"Well, we should hit the top of the stratosphere in less than an hour," the navigator replied. "From there on down—at reduced speed—will probably take another two hours."

"In that case," said Dynamon, "I think we'd better shut down on all conversation. Even Argallum doesn't know what we're bringing back—I'm taking no chances on having our secret get out to the enemy. He only knows that we are returning with two captured Martian Carriers. So, make your dispositions, Borion, because in five minutes I'm going to order everyone on all three ships to landing stations."

The next three hours were tense ones for the returning expedition. Even though a convoy had been promised, Dynamon was apprehensive about possible attacks by the Martians, who, he was sure, must know something of what was going on. But as it worked out, a perfect cloud of gray Cosmos Carriers came out to meet the voyagers from Saturn, and Dynamon was able to set his ships down at Vanadium Field without mishap.

A heavy guard was thrown around the precious cargoes, and the young centurion was whisked away to Government City.

"What did you find?" The Commander-in-Chief's face was haggard.

"We found tridium," said Dynamon, "tons of it. We had an opportunity to test it, and it proved to be a complete defense against the Ray."

"How difficult is it to get at?"

"Not difficult at all," said Dynamon, "we brought back enough to equip nearly ten thousand men."

"Heaven be praised!" said Argallum fervently, "We might pull out of this situation yet. Those devils have been sweeping everything before them. We cut off their communications with our air power but that didn't stop them. They've been living off the land, and they're so powerful that they've been able to overrun territory at will."

Dynamon glanced at his watch. "It is almost noon," he said, "It will take just one counter-attack to break through their line and roll it up in both directions. If you throw attack-units forward as fast as they can be equipped with tridium, you will have the Martians in a rout before sundown."

And it was so.

Dynamon stood beside Argallum two hours later, on a little knoll sixty miles out of Copia. A wide plain stretched before their eyes and across its width, a beaten, discouraged army of humans gave ground slowly before hordes of tiny, malevolent creatures from another planet. As the two men watched, a fresh column of Earth-soldiers issued forth from a woods in the center of the plain. There was a curious greenish shimmer surrounding this new column—a will-o'-the-wisp, mirage-like quality—and it advanced without hesitation straight into the serried ranks of the terrible Martians.

"Great Heavens!" cried Argallum, "They're walking right up to them! And not a man is down! Look! The Martians are reeling back! Our voltage bombs are killing them like flies!"

Dynamon turned away from the scene of carnage with a curious smile. He knew that Argallum in his gratitude would probably want to throw every conceivable honor and promotion at him. For bringing three Carrier loads of tridium back from Saturn, he, Dynamon, would very likely become a World-wide hero. And yet, he reflected, it was a feat which could never have been accomplished if it hadn't been for a series of unrelated incidents. If Keltry hadn't stowed away, she couldn't have fallen down the pit, thus leading to the discovery of Queen Diana's Nether World. If Mortoch had not rebelled and tried to kill him with a voltage bomb—. If he hadn't happened to touch the rock with his back—.

Dynamon turned and looked out on to the battle field where the victorious Earth-soldiers in their tridium-auras were vengefully slaughtering the hideous Martians. And he thought of the incident which had to precede all the other incidents so that he could bring back the tridium. That was the incident which had occurred hundreds of years before, when a man named Leonard Bolton had built a "space ship" and had traveled to Saturn in it, breaking through the burnt-out crust into the Nether World, boring the long hole with his clumsy medieval Carrier. That was the hole that Keltry had fallen into.

Dynamon shook his head. Leonard Bolton had built his "space ship" in the year 1956, the last year but one of the long series of frightful wars, in which the divided peoples of the World tried to destroy one another—and very nearly succeeded.