"Martin Larkwell was a good boy," the superintendent said reminiscently, "and of course we're highly pleased he's made his mark in the world." He looked at the agent and beamed. "Or should I say the moon?" The agent smiled dutifully.

"Young Martin was particularly good with his hands. Not that he wasn't smart," he added hurriedly. "He was very bright, in fact, but he was fortunate in that he coupled it with an almost uncanny knack of using his hands."

The superintendent rambled at length. The agent listened, thinking it was the same old story. The men in the moon were all great men. They had been fine, upstanding boys, all bright with spotless records. Well, of course that was to be expected in view of the rigorous weeding out program which had resulted in their selections. Only one of them was a traitor. Which one? The question drummed against his mind.

"Martin wasn't just a study drudge," the superintendent was saying. "He was a fine athlete. The star forward of the Maple Hill Orphanage basketball team for three years," he added proudly. He leaned forward and lowered his voice as if taking the agent into his confidence.

"We're conducting a drive to build the orphanage a new gym. Maybe you can guess the name we've selected for it?"

"The Martin Larkwell Gymnasium," the agent said drily.

"Right." The superintendent beamed. "That's how much we think of Martin Larkwell."

As it turned out, the superintendent wasn't the only one who remembered Martin Larkwell with fondness. A druggist, a grocer, a gas station operator and a little gray lady who ran a pet shop remembered the orphan boy with surprising affection. They and many others. That's the way the chips fall, the agent thought philosophically. Let a man become famous and the whole world remembers him. Well, his job was to separate the wheat from the chaff.

In the days to follow he painstakingly traced Martin Larkwell's trail from the Maple Hill Orphanage to New York, to various construction jobs along the East Coast and, finally, through other agents, to a two-year stint in Argentina as construction boss for an American equipment firm. Later the trail led back to America and, finally, to construction foreman on Project Step One. His selection as a member of the Aztec Crew stemmed from his excellent work and construction ability displayed during building of the drones. All in all, the agent thought, the record was clear and shiny bright.

Martin Larkwell, Gordon Nagel, Max Prochaska, Adam Crag—four eager scrub-faced American boys, each outstanding in his field. There was only one hitch. Who was the traitor?

Crag filled Gotch in on the latest developments in Crater Arzachel. The Colonel listened without interruption until he was through, then retaliated with a barrage of questions. What was the extent of the radioactive field? What were the dimensions of Red Dog? Had any progress been made toward salvaging the cargo of Drone Baker? How was the airlock in the rill progressing? Would he please describe the rocket launcher the enemy had used to destroy the Aztec? Crag gritted his teeth to keep from exploding, barely managing civil replies. Finally he could hold it no longer.

"Listen," he grated, "this is a four-man crew, not a damn army."

"Certainly," Gotch interrupted, "I appreciate your difficulties. I was just—in a manner of speaking—outlining what has to be done."

"As if I didn't know."

The Colonel pressed for his future plans. Crag told him what he thought in no uncertain terms. When he finished he thought he heard a soft chuckle over the earphones. Damn Gotch, he thought, the man is a sadist. The Colonel gave him another morsel of information—a tidbit that mollified him.

Pickering Field, Gotch informed him, was now the official name of the landing site in Crater Arzachel. Furthermore, the Air Force was petitioning the Joint Chiefs to make it an official part of the U.S. Air Force defense system. A fact which had been announced to the world. Furthermore, the United States had petitioned the U.N. to recognize its sovereignty over the moon. Before cutting off he added one last bit of information, switching to moon code to give it.

"Atom job near completion," he spelled out. For the moment Crag felt jubilant. An atom-powered space ship spelled complete victory over the Eastern World. It also meant Venus ... Mars ... magical names in his mind. Man was on his way to the stars. MAN—the peripatetic quester. For just an instant he felt a pang of jealousy. He'd be pinned to his vacuum while men were conquering the planets. Or would he? But the mood passed. Pickering Field, he realized, would play an important role in the future of space flight. If it weren't the stars, at least it was the jump-off. In time it would be a vast Air Force Base housing rockets instead of stratojets. Pickering Base—the jump-off—the road to the stars. Pretty soon the place would be filled with rank so high that the bird colonels would be doing mess duty. But right now, he was Mr. Pickering Field, the Man with the Brass Eyeballs.

While the others caught up on their sleep, Crag and Prochaska reviewed their homework, as the Chief had dubbed their planning sessions. The area in which Bandit rested was too far from the nearest rill to use as a base of operation, and it was also vulnerable to meteorite damage. Bandit had to be abandoned, and soon. Red Dog would be their next home. There was also the problem of salvaging the contents of Drone Baker and removing the contents of Drone Charlie. Last, there was the problem of building the airlock in one of the rills. When they had laid out the problems, they exchanged quizzical glances. The Chief smiled weakly.

"Seems like a pretty big order."

"A very big order," Crag amended. "The first move is to secure Red Dog." They talked about it until Crag found his eyelids growing heavy. Prochaska, although tired, volunteered to take the watch. Crag nodded gratefully—a little sleep was something he could use.

Red Dog was squat, ebony, taper-nosed, distinguishable from the lithic structures dotting this section of Crater Arzachel only by its symmetry. The grotesque rock ledges, needle-sharp pinnacles and twisted formations of the plain clearly were the handiwork of a nature in the throes of birth, when volcanoes burst and the floor of the crater was an uneasy sea of white-hot magmatic rock. Red Dog was just as clearly the creation of some other-world artificer, a creature born of the intelligence and patience of man, structured to cross the planetary voids. Yet it seemed a part of the plain, as ancient as the brooding dolomites and diorites which made the floor of Arzachel a lithic wonderland. The tail of Red Dog was buried in the ash of the plain. Its body reached upward, canted slightly from the vertical, as if it were ready to spring again to the stars.

The rocket launcher had been removed. Now it stood on the plain off to one side of the rocket, small and portable, like some deadly insect. The launcher bothered Crag. He wanted to destroy it—or the single missile that remained—but was deterred by its possible use if the enemy should land another manned ship. In the end he left it where it was.

One of the numerous rills which crisscrossed the floor of the crater cut near the base of the rocket at a distance of about ten yards. It was a shallow rill, about twelve feet wide and ten feet deep, with a bottom of soft ash.

Adam Crag studied the rocket and rill in turn, a plan gradually forming in his mind. The rocket could be toppled, its engines removed and an airlock installed in the tail section, as had been done with the Aztec. It could be lowered into the rill and its body, all except the airlock, covered with ash. Materials salvaged from the drones could be used to construct extensions running along the floor of the rill and these, in turn, covered with ash. This, then, would be the first moonlock, a place where man could live, safe from the constant danger of destruction by chance meteorites.

He looked thoughtfully at the sun. It was an unbearable circle of white light hanging in the purple-black sky just above the horizon. Giant black shadows crept out from the towering walls of the crater. Within another twenty-four hours they would engulf the rocket. During the lunar night—two weeks long—the crater floor would be gripped in the cold of absolute space; the rocket would lie in a stygian night broken only by the brilliance of the stars and the reflected light of an earth which would seem to fill the sky. But they couldn't wait for the advent of a new day. They would have to get started immediately.

Larkwell opposed the idea of working through the long lunar night. He argued that the suits would not offer sufficient protection against the cold, they needed light to work, and that the slow progress they would make wouldn't warrant the risks and discomfort they would have to undergo. Nagel unexpectedly sided with Crag. He cited the waste of oxygen which resulted by having to decompress Bandit every time someone left or entered the ship.

"We need an airlock, and soon," he said.

Crag listened and weighed the arguments. Larkwell was right. The space suits weren't made to withstand prolonged exposure during the bitter hours of the lunar night. But Nagel was right, too.

"I doubt if we could live cooped up in Bandit for two weeks without murdering one another," Prochaska observed quietly. "I vote we go ahead."

"Sure, you sit on your fanny and monitor the radio," Larkwell growled. "I'm the guy who has to carry the load."

Prochaska reddened and started to answer when Crag cut in: "Cut the damned bickering," he snapped. "Max handles the communication because that's his job." He looked sharply at Larkwell. The construction boss grunted but didn't reply.

Night and bitter cold came to Crater Arzachel with a staggering blow. Instantly the plain became a black pit lighted only by the stars and the enormous crescent of the earth—an airless pit in which the temperature plunged until metal became as brittle as glass and the materials of the space suits stiffened until Crag feared they would crack.

Larkwell warned against continuing their work.

"One misstep in lowering Red Dog and it'll shatter like an egg."

Crag realized he was right. Lowering the rocket in the bitter cold and blackness would be a superhuman job. Loss of the rocket would be disastrous. Against this was the necessity of obtaining shelter from the meteor falls. His determination was fortified by the discovery that a stray meteorite had smashed the nose of Drone Charlie. He decided to go on.

The cold seeped through their suits, chilled their bones, touched their arms and legs like a thousand pin pricks and lay like needles in their lungs until every movement was sheer agony. Yet their survival depended upon movement, hence every moment away from Bandit was filled with forced activity. But even the space cabin of Bandit was more like an outsized icebox than a place designed for human habitation. The rocket's insulated walls were ice to the touch, their breaths were frosty streams—sleep was possible only because of utter fatigue. At the end of each work shift the body simply rebelled against the task of retaining consciousness. Thus a few hours of merciful respite against the cold was obtained.

Crag assigned Prochaska the task of monitoring the radio despite his plea to share in the more arduous work. The knowledge that one of his crew was a saboteur lay constantly in his mind. He had risked leaving Prochaska alone before, he could risk it again, but he wasn't willing to risk leaving any of the others alone in Bandit. Yet, Prochaska hadn't found the bomb! Larkwell had worked superhumanly at the task of rebuilding the Aztec—Nagel had saved his life when he could just as easily have let him die. Neither seemed the work of a saboteur. Yet the cold fact remained—there was a saboteur!

Richter, too, preyed on his mind. The self-styled Eastern scientist was noncommittal, speaking only when spoken to. Yet he performed his assigned duties without hesitation. He had, in fact, made himself so useful that he almost seemed one of the crew. That, Crag told himself, was the danger. The tendency was to stop watching Richter, to trust him farther and farther. Was he planning, biding his time, preparing to strike? How? When? He wished he knew.

They toppled Red Dog in the dark of the moon.

Larkwell had run two cables to manually operated winches set about twenty-five yards from the rocket. A second line extended from each winch to the ravine. The ends of these were weighted with rocks. They served to anchor the winches during the lowering of the rocket. Finally a guide line ran from the nose of the rocket to a third winch. Richter and Nagel manned the lowering winches while Larkwell worked with the guide line, with only small hand torches to aid them. It was approximately the same setup used on the Aztec—they were getting good at it. Crag helped until the moment came to lower the rocket, then there was little for him to do. He contented himself with watching the operation, playing his torch over the scene as he felt it was needed.

It was an eery feeling. The rocket was a black monster bathed in the puny yellow rays of their hand torches. The pale light gave the illusion of movement until the rocket, the rocks, and the very floor of the crater seemed to writhe and squirm, playing tricks on the eyes. It was, he knew, a dangerous moment, one ripe for a saboteur to strike—or ripe for Richter.

It was dark. Not an ebony dark but one, rather, with the odd color of milky velvet. The earth was almost full, a gigantic globe whose reflected light washed out the brilliance of the stars and gave a milky sheen to Crater Arzachel. It was a light in which the eye detected form as if it were looking through a murky sea. It detected form but missed detail. Only the gross structures of the plain were visible: the blackness of the rocket reaching upward into the night; fantastic twisted rocks which blotted out segments of the stars; the black blobs of men moving in heavy space suits, dark shadows against the still darker night. The eery almost futile beams of the hand torches seemed worse than useless.

"All set." Larkwell's voice was grim. "Let her come."

Crag fastened his eyes on the nose of Red Dog, a tapered indistinct silhouette.

"Start letting out line at the count of three." There was a pause before Larkwell began the countdown.

"One ... two ... three...."

The nose moved, swinging slowly across the sky, then began falling.

"Slack off!"

The lines jerked, snapped taut, and the nose hung suspended in space, then began swinging to one side.

"Take up on your line, Richter." The sideward movement stopped, leaving the rocket canted at an angle of about forty-five degrees.

"Okay...." The nose moved down again, slower this time. Crag began to breathe easier. Suddenly the nose skidded to the rear, falling, then the rocket was a motionless blob on the plain.

"That did it." Larkwell's voice was ominous, yet tinged with disgust.

"What happened?" Crag found himself shouting into the lip mike.

"The tail slipped. That's what we get for trying to lower it under these conditions," Larkwell snarled. "The damn thing's probably smashed."

Crag didn't answer. He moved slowly toward the rocket, playing his torch over its hull in an attempt to discern its details. He was conscious that the others had come up and were doing the same thing, but even when he stood next to it Red Dog was no more than a black shadow.

"Feel it," Larkwell barked, "that's the only way to tell. The torches are useless." They followed his advice. Crag walked alongside the rocket, moving his hand over the smooth surface. He had reached the tail and started back on the opposite side when Larkwell's voice rang in his ears.

"Smashed!"

"Where?"

"The under side—where she hit the deck. Looks like she came down on a rock."

Crag hurried back around the rocket, nearly stumbling over Larkwell's legs. The construction boss was lying on his stomach.

"Under here." Crag dropped to his knees, then to his stomach and moved alongside Larkwell, playing his beam over the hull. He saw the break immediately, a ragged, gaping hole where the metal had shattered against a small rock outcropping. Too big for a weld? Larkwell answered his unspoken thought.

"You'll play hell getting that welded."

"It might be possible."

"There may be more breaks." They lay there for a moment playing their beams along the visible underside of Red Dog until they were satisfied that, in this section at least, there was no more damage.

"What now?" Larkwell asked, when they had crawled back from under the rocket.

"The plans haven't changed," Crag said stonily. "We repair it ... fix it up ... move in. That's all there is to it."

"You can't fix it by just saying so," Larkwell growled. "First it's got to be fixable. It looks like a cooked duck, to me."

"We gotta start back," Nagel said urgently, "oxygen's getting low."

Crag looked at his gauge. Nagel was right. They'd have to get moving. He was about to give the signal to return to Bandit when Richter spoke up.

"It can be repaired." For a moment there was a startled silence.

"How?"

"The inside of the cabin is lined with foam rubber, the same as in Bandit—a self-sealing type designed for protection against meteorite damage."

"So...?" Larkwell asked belligerently.

Richter explained, "It's not porous. If the break were covered with metal and lined with the foam, it would do a pretty good job of sealing the cabin."

"You can't patch a leak that big with rubber and expect it to hold," Larkwell argued. "Hell, the pressure would blow right through."

"Not if you lined the break with metal first," Richter persisted.

The suggestion startled Crag, coming as it did from a man whom he regarded as an enemy. For a moment he wondered if the German's instinct for survival were greater than his patriotism. But the plan sounded plausible.

He asked Larkwell: "What do you think?"

"Could be," he replied noncommittally. He didn't seem pleased that Richter was intruding in a sphere which he considered his own.

Crag gave a last look at the silhouette of the fallen giant on the plain and announced: "We'll try it."

"If it doesn't work, we're in the soup," Larkwell insisted. "Suppose there are more breaks?"

"We'll patch those, too," Crag snapped. He felt an unreasonable surge of anger toward the construction boss. He sucked his lip, vexedly, then turned his torch on his oxygen meter. "We'd better get moving."