At his brother's eager cry, Jon ran over toward where the older boy was stooping down, examining carefully something almost completely embedded in the sand. He saw Jak rise, take his shovel from the carrying straps on his suit's back, and start uncovering whatever it was he had stumbled over.

As Jon came up, he uttered an exclamation of surprise. "Why ... what ... that's a metal plate. What is it, Jak?"

"Don't ... know ... yet," the elder panted as he worked even more feverishly with his shovel. Jon quickly laid down the detector, which was clicking excitedly, to unsling his own shovel and begin digging.

In a few moments they had completely bared the metal plate, and could now see it was about ten by four feet, and hinged on one side.

"Looks like a trap door."

"Sure does. Lend a hand—let's see if we can open it."

The crack along the edge was not wide enough for the gloved fingers of their suits, so Jon inserted his shovel tip in the crack as a prize. Jak did the same and after many attempts—for it was much heavier even than they expected—they managed to lift the edge a bit.

"Can you hold it alone a sec?" Jak asked.

"Try," Jon threw his whole weight on the end of the shovel handle, while Jak quickly found a small stone and wedged it in the opening. Then, with Jon moving his shovel farther and farther back along the edge, Jak pushed ever larger stones closely behind him, and they finally managed to get the cover high enough so they were able to tip it back, but only after considerable straining and puffing.

"What do you suppose is down there?" Jon hopped about, digging at the sand with his boot tip.

"Don't know, but it has sure been a long time since anyone used this." Jak spoke slowly.

"How can you tell?"

"Because of all the sand that's sifted in here, silly. You don't think this is just a box of sand, do you? It could have been here thousands and thousands of years."

"You mean ... there were people living here then?"

The elder boy shook his head. "Maybe yes, maybe no. It could have been folks who merely visited here. Well, what do we do now?"

Jon picked up his shovel. "You're the one that's silly now. We clear it out and look."

For some time the two made the sand fly, then Jak's shovel struck metal, and feverishly the two concentrated on that spot. Another few minutes and they could see it was a large metal chest that almost filled this covered, metal-lined pit. When they finally had the top of the box completely exposed, they found its cover fastened with a simple hasp, which was quickly opened. Then they lifted this second lid.

Inside, the box was completely filled with thousands of small cubes of some sort of glistening metal. Jak started to reach for one but Jon struck his hand away.

"Listen to that detector—it has gone crazy," he yelled. "That stuff's deadly radioactive, I bet." He started to scramble out of the hole after slamming down the lid. "We get out of here, but fast. Then we talk about it."

Jak had sense enough to heed his brother's warning, and lost no time in following. Some little distance away, the two stopped to debate what they were to do.

"You know what I think?" Jon's eyes gleamed. "I think this was a fuel cache left by people who used to make trips around the galaxy, and not something left by people who once lived here."

"You're nuts. Who—and when—and why didn't they ever come to Terra, if they had space-flight? If they came this close, wouldn't they have gone there, too?"

"Not necessarily—space is so big and Sol is relatively small, you know. But maybe they did get to Earth, at that." Jon grew more thoughtful. "Remember our reading about all the strange things people reported seeing, hundreds...."

"You mean those old 'flying saucer' reports a couple of centuries ago?"

"Yes, them. And even before that, there'd been reports of strange airships and things. Why, there was one—that's almost four hundred years ago—of a Dutch sea captain who saw something in the air above the Indi Ocean and reported it in his log. Even made a sketch of it, that was almost exactly like those made later by people who said they'd seen it."

"Mmmm," Jak had been thinking back, "then maybe the Bible story of Ezekiel's 'wheel within a wheel' he saw in the air, was one?"

"Sure. Earth people for centuries have seen all sorts of unknown things."

"Then maybe your idea isn't so wild, after all."

"The question now is," Jon ignored the apology, "how do we take some of this stuff back to the ship, and how do we test it to see if it's fuel—or don't we?"

"That's more your line than mine. What do you suggest?"

Jon thought seriously for several minutes, then brightened. "You stay here so I can see where I'm going, and I'll go get the ship and bring it here. Then we'll try one of those cubes in the generator."

"You ... you think it's safe?"

"What would get you, out here in this desert?"

"I didn't mean that, and you know it. I meant, do you think it's safe to try this stuff that way?"

"Oh, that? Sure." Jon threw down the extra things he was carrying, and started away at a trot.

When he reached the ship and was inside the airlocks, he called to his mother as he was sitting down at the controls.

"What's the matter, Jon?" she asked as she came in and saw him working at the controls. "And where's Jak?"

"We found something out there too heavy to carry, and Jak's watching it while I bring up the ship. Strap down."

She sank into the co-pilot's seat and fastened the broad belt about her even as Jon was activating the generator and tubes. Raggedly, since he was trying to handle the controls and read the directions at the same time—it simply didn't occur to him to ask his mother to read them to him—the boy finally got the ship into the air.

"What is it you've found?" His mother could contain her curiosity no longer.

"Something we think is that new fuel Pop talked about, but it's radioactive and we didn't dare try to carry it without special equipment," he told her absently as the ship began lowering.

He maneuvered it to a bumpy landing close to his brother, whom they could now see through the port, excitedly waving his arms at them. "We think it's something some other people left here as a cache, a long, long time ago," Jon explained as he put his controls in neutral, his voice an excited squeak.

"Some other Earth people?" she asked incredulously. "You mean we aren't the first ones here, after all?"

"No, we don't think it was Terrans," he said as he unstrapped. But before he could get out of the seat, they heard the lockdoor mechanisms working, and knew Jak was coming inboard, so the two stayed in the control room. Jon answered his mother's anxious questions as best he could.

Jak soon came running in and the two boys held a quick council, almost ignoring their mother in the excitement of trying to figure a safe way of bringing some of the fuel-stuff aboard and trying it out.

But at last she made herself heard. "I think you should wait and let Mr. C. decide about this," she said with determination.

"How is he—awake?"

"About the same—still unconscious."

"Then don't you see, Mom, that there's no telling when he'll wake up, and we don't want to wait that long?"

"I still say you mustn't take the chance of blowing us all to Kingdom Come before you can have his advice and help in deciding what to do with that new, untried and dangerous metal," she declared so firmly that they could not ignore her. "Now you listen to your mother. This is once when I'm setting my foot down. I will not let you do it!"

Nor could their pleas move her.

"All right, Mother," Jak finally conceded defeat with—if the truth must be told—an inner sense of relief. He, too, had been more than a little afraid of that untried stuff. But Jon had seemed so sure, while he knew very little about it. "We'll leave it here while we go set our markers on the other planets."

"Unless Pop wakes up before we're finished here," Jon added sullenly, somewhat humiliated because he felt his mother was treating him like a little boy instead of the man and scientist he now considered himself to be. "When he does, though, you'll see he'll say we should have tried it."

His mother, understanding well how he felt, but still worried over the possibilities for danger her anxious mind insisted on painting, patted his shoulder. "In that case, Son," she said softly, "I'll apologize."

"We'd better go out and shut that trap door and mark the place some way before we leave." Jak tried to lighten the tension.

"I'll take measurements of where we are, and that'll do just as well." Jon's voice still held that injured tone.

Mrs. Carver kept her voice level, but her eyes caught and held those of her younger son. "I'm sorry if I seem too stubborn about this, Jon; but I just don't like the idea of you boys trying to handle, alone, something you don't know anything about, especially since you yourselves admit that it's highly dangerous."

Jon's petulance slowly disappeared, and finally he grinned and kissed her. "You're right, as always, Mom. I'm getting too big for my coveralls. I'll calculate courses to One, and to and around the sun, and we'll let this ride until Pop wakes up."

While Jak and Mrs. Carver busied themselves at other tasks, Jon sweated over the complicated math of the new courses. He knew how important this was, especially the plan he had in mind for placing the marker in its orbit about the sun. He knew their very lives depended on the correctness of his calculations. So he did them slowly, carefully, and checked them closely to make sure he had done them right and made no mistakes.

But when he was finished, he put the sheets of calculations in a drawer, took more paper and figured the courses over a second time. That solution he also put in the drawer, and figured it the third time, without consulting what he had done before.

When he had completed this third computation he took out the other two sets and compared the three. All came out exactly the same ... and he gasped in relief and sank back, trembling with thankfulness, in the pilot's seat. They must be right.

---

While Mrs. Carver and her sons were eating lunch they heard a weak call from the bunkroom, and ran in to find their father fully awake. He seemed surprised at his condition, but Jak explained swiftly what had happened, and Jon told briefly what they had done and were planning to do next.

"That's good; that's very good," he said drowsily, and before Jon could say anything about finding that new metal, his father had again sunk into sleep—or unconsciousness; not even Jak could tell which.

"Well," Jon tried to be brave about his disappointment, "I guess we'll just have to go ahead. But isn't it swell that Pop woke up fully?"

"It certainly is." Mrs. Carver had tears of joy in her eyes. "Now we know he'll soon be all right."

The trip to Planet One—"Tad"—was neither long nor eventful, once they got started. They found, as expected, that the small world—smaller than Sol's Mercury—was so close to the sun that it was fearfully hot, even on the equator, or "intermediate" zone.

Despite the refrigerators on the ship, it was becoming hot inside, and all stripped as far as decency allowed. The planet had no real atmosphere, but many of the metals—indeed, the very rocks, themselves—were so largely molten, especially on the eternally sunward side, that there was a fog of gasses about the surface. These gaseous emanations were in a state of motion much like that of Earthly cyclones, constantly swirling and blowing with terrific velocity.

The boys carefully examined their spectro-analyzer, but "Annie" showed none of that strange fuel-metal they were so keen to locate in its natural state. "Maybe we found all there is here," Jak suggested.

"Perhaps, but somehow I can't feel that way." Jon's voice was worried. "I must have slipped somewhere. Don't see how just one boxful could have shown up so clearly from as many light years away as we first discovered it."

Despite the conditions the young planet mappers found here on One, the Colonial law required that a sending beacon be set up on ALL planets, or else in an orbit about them. They decided to place theirs on top of one of the highest of the small mountains that comprised the twilight zone.

Jon made up the tape for this planet's signal-marker, while Jak brought it from the storeroom. When the tape was installed and running, the sender was placed in the lock between the inner and outer doors, and the boys returned to the control room.

Jon directed the ship toward the range of mountains and when he neared them Jak—from his co-pilot's seat—worked the remote controls and the outer lockdoor swung open. Then he activated the "distant hands"—the handling mechanism that was an integral part of the airlock's equipment, for handling materials into and out of the ship.

Watching through his special visiplate—really a sort of two-way television—Jak made the grips pick up the signal-sender box, ready to deposit it on the hard, hot ground outside when Jon would swoop down over the pre-selected mountaintop.

"Move it outside," Jon called, and Jak did so. "Set it down." Jon yelled, and as soon as he was sure Jak had placed the sender solidly, sent the space-yacht rising higher and away from the planet. Then Jak closed the outer door; turned in his co-pilot's seat, and tuned in their receiver. Soon they caught the message and knew everything was jetting fair.

"Nice going, Owl," Jon applauded.

"Aw, you're just saying that because it's true," Jak grunted, and Jon turned his attention once more to his controls and the new course he had plotted for their swing around the sun of this system, now less than thirty million miles away.

"How close d'you go?" Jak was more interested than fearful, having confidence in his brother's skill.

"We have to follow a course so that when the sender is dumped, it will take up a closed orbit—the more nearly circular the better—around the sun. Also, we'll have to have speed enough so we won't get fried to a crisp at the near-point, which figures to be about ten million miles."

"Isn't that pretty close?" their mother, who had slipped into the control room quietly just after Jak had placed the sender, tried not to sound too frightened.

"Relax, Mother, the kid knows what he's doing," Jak tried to calm her.

"I've figured this three times, Mom," Jon said earnestly. "Got the same answer each time, so I know we can do it."

"Well," still doubtfully, "I guess you do know what you are doing, but that seems awfully close." She struggled with herself and finally managed a weak smile. "I promised to let you boys make the decisions. I'll go lie down in my bunk so I won't know what's happening until it's all over."

"You do that, Mother. I'm not worrying. Jon really knows his stuff," Jak assured her brightly. But as soon as she had left the control room, he turned worried eyes to his brother. "I ... I hope you actually do, Chubby." His voice quavered a bit.

Jon grinned mockingly. "There's one sure thing. If I'm wrong, we'll never know it. But I've studied this a lot since I knew it was up to me. I know the technique and, as I said before, I've computed our course three times and come up with the same figures each time. And we have to set it as close as possible. Now, either hit your bunk or set your seat to recline. We're up to better than two G's already, and I'm building to five."

"Yes, I feel us getting heavier. I'll stay with you." Jak made sure his straps were in place, then tilted his seat.

Jon cranked his own to recline, the control panel automatically slanting to keep it in the same relative position. His arms were resting on movable slides, and the controls he would have to manipulate on this dangerous orbit were all beneath his hands and fingers.

Closer and closer they drove to the sun with ever mounting speed. Their gallant little ship's refrigerators were full on; all shutters in place. Their only view of the outside was through one visiplate whose aperture was closed until only a tiny slit was open. But it was enough, although Jon was forced to keep building up layer after layer of protective, colored plastic to make the intense, blinding light of the swiftly approaching sun bearable.

Clearly visible now were the tremendous streamers of matter the sun was throwing up as prominences. Jon was able to see huge sunspots occurring here and there about the surface of that mighty furnace—tremendous cyclonic storms of atomic disintegration. So interested was he in this first close view of a sun that he almost forgot the reason for this dangerous trip.

Almost—but not quite, for his mind was well-trained to remember the things that had to be recalled, young as he was. So his eyes glanced often at the distance gauge. Soon he yelled at Jak, "Get ready to throw out the sender."

Jak struggled to place his hands on the controls, a thing he had not had the foresight to do before Jon started building up that tremendous acceleration. His muscles strained. Sweat broke out on him even worse than that the heat from the sun brought. His breathing became gasps. There seemed to be a constricting band about his chest. His eyes felt as though the balls were being pushed down into his head. He just couldn't possibly move a muscle under this terrible pressure.

Still he exerted every force of will and of muscle. Slowly, painfully, he stretched out his fingertips a fraction of an inch. He dug them into the fabric of the arm rest and pulled the palm of his hand along. Then he forced the rest of his arm to follow his fingers and hand. Over and over, straining to do what had to be done. Then victory at last—his hand and arm were on the sliding arms. Now it was easier, and soon his fingers were on the controls.

"S-say when," he panted then.

"Open the outer door now ... we're almost there," Jon commanded, watching his controls intently. "We're going ... so fast ... won't have ... much time."

"You're sure ... sender'll keep ... correct orbit?"

"Sure," Jon's voice was confident. "If we don't dump ... exactly on zero ... it'll just change shape ... of orbit a little ... that's all."

"Door open," Jak reported a moment later.

"Lift sender, but don't eject yet."

"Right."

More minutes while the heat increased, and even through that tiny aperture and the covering shields, the blinding light was coming in so fiercely Jon was tempted to close it entirely. Then, with a snort of disgust at his stupidity, he did close it—and breathed a sigh of relief as that piercing beam died. He didn't need to see. There was no reason to look. Even if there was, it was too late now to do anything about it. If his calculations were correct, the ship would get away safely. If his figures were wrong ... he shuddered. Well, they'd never know it, that was for sure.

He made himself forget that dire possibility and kept his eyes glued to his indicators.

"Almost there."

"Ready." Jak tensed his hand and fingers above the controls. He hoped he could do it when the time came. But this awful heat ... this horrible acceleration pressure....

"Drop it!" Jon yelled suddenly.

Jak tensed hand and fingers and tried to depress the button. It seemed he couldn't move. He gritted his teeth, and again called upon his inner strength, his will. From that hidden depth he found that extra measure of energy necessary to curve his fingertip downward.

His eyes, peering into the shielded intercom visiplate, saw those distant hands—the servo-mechanism in the lock—swing the box out through the opened doorway. When he could no longer see it, because of the angle at which his visiplate was set, he touched and depressed the second button. Now, if the mechanism was still functioning in spite of that terrific heat, its arms were opening and the box slipping away.

He withdrew the handling arms, and as they came into sight again he saw with satisfaction that they were empty. He locked them into their cradle, then closed the outer lockdoor.

"Done," he reported thankfully ... and let himself go. Unconsciousness claimed him at once. Why suffer, had been his thought, when he could so easily sleep until this intolerable pressure was gone.

So quickly did he slip away he did not realize that Jon, too, after a final quick glance at his board, and knowing that everything necessary had been done, had also relaxed into unconsciousness. Did not know, or care, that their ship was now speeding around and away from the sun. Did not realize that all four of the Carvers were now unconscious.

But their blackout did not last too long. In a few hours, during which the auto-pilot took them smoothly and accurately away from that titanic furnace, safety distance was attained and the frightful acceleration began to ease.

By the time they were traveling at a little less than two gravities, Jon stirred. His memory cells began functioning once more, and slowly he awakened. As soon as he realized where he was, and why, he glanced at his various telltales.

"We made it!" he yelled triumphantly. Then, as he heard no reply from his brother, he quickly raised his seat to upright, and turned to look at Jak. The latter was still lying down, his face white and strained.

Quickly, anxiously, Jon released himself and sprang across to his brother's side. He rubbed Jak's wrists and temples. Soon the flush of returning blood showed, and the elder sighed and opened his eyes.

"We made it!" Jon cried again as he pushed Jak's seat into erect. "Everything went off shark-y."

Jak struggled into full consciousness, then began loosening his straps. "Mother and Father?" he exclaimed. "Did they come through all right?"

---