Crag studied the scene. He lay at one end of the great crescent of rock forming Backbone Ridge, the other end of which ended about half a mile from Red Dog. The floor of the crater between the rocket and the nearest rock formations was fairly level and unbroken. The arced formation itself was a veritable jungle of rocks of every type—gnarled, twisted rock that hugged the ground, jutting black pinnacles piercing the sky, bizarre bubble formations which appeared like weird ebony eskimo cities, and great fantastic ledges which extruded from the earth at varying angles, forming black caves against their bases.

Whole armies could hide there, he thought. Only the fugitive couldn't hide. Oxygen was still the paramount issue. He'd have to thread his way through the terrible rock jungle to the distant tip of the crescent, then plunge across the open plain to the rocket if he hoped to survive. The distance between the horns of the crescent appeared about three miles. He pondered it thoughtfully, then got on the interphones and outlined his plan to Prochaska.

"Okay, I know better than to argue," the Chief said dolefully when he had finished. "But watch your oxygen." Damn the oxygen, Crag thought irritably. He studied the labyrinth of rock into which his quarry had vanished, then rose and started across the plain in a direct line for the opposite tip of the crescent.

The first moments were the hardest. After that he knew he must be almost out of range of the sniper's weapon. Perhaps, even, the other had not seen his maneuver. He forced himself into a slow trot, his breath whistling in his ears and his body sodden inside his suit. Perspiration stung his eyes, his leg muscles ached almost intolerably, and every movement seemed made on sheer will power. The whimsical thought crossed his mind that Gotch had never painted this side of the picture. Nor was it mentioned in the manual of space survival.

He was thankful that the plain between the two tips of the crescent was fairly even. He moved quickly, but it was a long time before he reached the further tip of the crescent. He wondered if he had been observed from Red Dog. Well, no matter, he thought. He had cut the sniper's sole avenue of escape. Victory over his quarry was just a matter of time, a matter of waiting for him to appear. He picked a vantage point, a high rocky ledge which commanded all approaches to his position. After briefing Prochaska, he settled back to wait, thinking that the fugitive must be extremely low on oxygen.

Long minutes passed. Once or twice he thought he saw movement among the rocks and started to lift his rifle; but there was no movement. Illusions, he told himself. His eyes were playing him tricks. The bizarre sea of rocks confronting him was a study in black and white—the intolerable light of sun-struck surfaces contrasting with the stygian blackness of the shadows. His eyes began to ache and he shifted them from time to time to shut out the glare. He was sweating again and there was a dull ache at the back of his head. Precious time was fleeing. He'd have to resolve the chase—soon.

All at once he saw movement that was not an illusion. He half rose, raising his rifle when dust spurted from the ground a few feet to his left. He cursed and threw himself to the ground, rolling until he was well below the ridge. One thing was certain: the sniper had the ridge well under control. The Red Dog watcher must have warned him, he thought. He looked around. Off to one side a small rill cut through the rocks running in the sniper's general direction. He looked back toward the ridge, hesitated, then decided to gamble on the rill. He moved crablike along the side of the slope until he reached its edge and peered over. The bottom was a pool of darkness. He lowered himself over the edge with some misgivings, searching for holds with his hands and feet. His boot unexpectedly touched bottom.

Crag stood for a moment on the floor of the rill. His body was clothed in black velvet shadows but it was shallow enough to leave his head in the sunlight. He moved cautiously forward, half expecting the sniper to appear in front of him. His nerves were taut, edgy.

Relax, boy, you're strung like a violin, he told himself. Take it easy.

A bend in the rill cut off the sun leaving him in a well of blackness. He hadn't counted on that. Before he'd moved another dozen steps he realized the rill wasn't the answer. He'd have to chance getting back into the open. More time was lost. He felt the steep sides until he located a series of breaks in the wall, then slung his rifle over his shoulder and inched upward until his head cleared the edge. The sun's sudden glare blinded him. Involuntarily he jerked his head sideways, almost losing his hold in the process. He clung to the wall for a moment before laboriously pulling his body over the edge.

He lay prone against the rocks, half-expecting to be greeted by a hail of bullets. He waited quietly, without moving, then carefully raised his head. Off to one side was a series of mounds. He crawled toward them without moving his belly from the ground. When he reached the first one, he half rose and scuttled forward until he found a view of the twisted rocks where he had last seen the sniper.

The scene ahead was a still-life painting. It seemed incongruous that somewhere among the quiet rocks death moved in the form of a man. He decided against penetrating further into the tangle of rocks. He'd wait. He settled back, conscious that time was fleeing.

"Skipper, are you checking your oxygen?" The Chief's voice rattled against his eardrums. It was filled with alarm.

"Listen, I have no time—" Crag started to growl. His words were clipped short as his eyes involuntarily took the reading of his oxygen gauge. Low ... low. He calculated quickly. He was well past the point of no return—too low to make the long trip back to Bandit. He was done, gone, a plucked gosling. He had bought himself a coffin and he'd rest there for all eternity—boxed in by the weird tombstones of Crater Arzachel. Adam Crag—the Man in the Moon.

He grinned wryly. Well, at least his quarry was going with him. He wouldn't greet his Maker empty handed. He tersely informed Prochaska of his predicament, then recklessly moved to a high vantage point and scanned the rocks beyond.

He had to make every second count. Light and shadow ... light and shadow. Somewhere in the crisscross of light and shadow was a man-form, a blob of protoplasm like himself, a living thing that had to be stamped out before the last of his precious oxygen was gone. He was the executioner. Somewhere ahead a doomed man waited in the docks ... waited for him to come. They were two men from opposite sides of the world, battling to death in Hell's own backyard. Only he'd win ... win before he died.

He was scanning the rocky tableau when the sniper moved into his field of vision, far to one side of Crag's position. He was running with short choppy steps, threading between the rocks toward Red Dog. His haste and apparent disregard of exposing himself puzzled Crag for a moment, then he smiled grimly. Almost out of oxygen, he thought. Well, that makes two of us. But he still had to make sure his quarry died. The thought spurred him to action.

He turned and scrambled back toward the tip of Backbone Ridge to cut the sniper's escape route. He reached the end rocks and waited. A few moments later he sighted a figure scrambling toward him. He raised his rifle thinking it was too far for a shot, then lowered it again. The sniper began moving more slowly and cautiously, then became lost to sight in a maze of rock outcroppings.

Crag waited impatiently, aware that precious moments were fleeing. He was afraid to look at his gauge, plagued by the sense of vanishing moments. Time was running out and eternity was drawing near—near to Adam Crag as well as the sniper. The rocks extended before him, a kaleidoscopic pattern of black and white. Somewhere in the tortuous labyrinth was the man he had to kill before he himself died. He watched nervously, trying to suppress the tension pulling at his muscles. A nerve in his cheek twitched and he shook his head without removing his eyes from the rocks ahead. Still there was no sign of the other.

Who was the stalker and who was the stalked? The question bothered him. Perhaps even at that instant the sniper was drawing bead. Then he'd be free to reach Red Dog—safety.

Crag decided he couldn't wait. He'd have to seek the other out, somehow flush him from cover. He looked around. Off to one side a shelf of black rock angled incongruously into the sky. Its sides were steep but its top would command all approaches to the tip of the crescent. He made his way to the base of the shelf and began scrambling up its steep sides, finding it difficult to manage toe and hand holds. He slipped from time to time, hanging desperately on to keep himself from rolling back to the rocks below. Just below the top he rested, panting, fighting for breath, conscious of his heart thudding in his ears. He had to hurry!

Slowly, laboriously he pulled himself up the last few feet and lay panting atop the shelf, none too soon. The sniper scrambled out of the rocks a scant hundred yards from Crag's position. He raised his rifle, then hesitated. The Red Dog crewman had fallen to his hands and knees and was fighting to rise. He pushed his hands against the plain in an attempt to get his feet under him. Crag lowered his rifle and watched curiously.

The sniper finally succeeded in getting to his feet. He stood for a moment, weaving, before moving toward Crag's shelf with a faltering zigzag gait. Crag raised the rifle and tried to line the sights. He had difficulty holding the weapon steady. He started to pull the trigger when the man fell again. Crag hesitated. The sniper floundered in the ash, managed to pull himself half-erect. He weaved with a few faltering steps and plunged forward on his face.

Crag watched for a moment. There was no movement. The black blob of the suit lay with the stillness of the rocks in the brazen heat of the crater. So that's the way a man dies when his oxygen runs out, he thought. He just plops down, jerks a little and departs, with as little ceremony as that. He grinned crookedly, thinking he had just watched a rehearsal of his own demise. He watched for a moment longer before turning his face back toward the plain.

Red Dog was a bare half-mile away—a clear level half-mile from the tip of Backbone Ridge. That's how close the sniper had come to living. He mulled the thought with a momentary surge of hope. Red Dog? Why not? If he could shoot his way into the space cabin he'd live ... live. The thought galvanized him to action.

He slung his rifle over his shoulder and scrambled down the slope heedless of the danger of ripping his suit. He could make it. He had to make it! He gained the bottom and paused to catch his breath before starting toward the rocket. A glance at his oxygen meter told him that the race was futile. Still, he forced his legs into a run, threading through the rocks toward the floor of the crater. He reached the tip of the crescent panting heavily and plunged across the level floor of the plain. His legs were leaden, his lungs burned and sweat filled his eyes, stinging and blurring his vision. Still he ran.

The rocket rose from the crater floor, growing larger, larger. He tried to keep in a straight path, aware that he was moving in a crazy zigzag course.

The rocket loomed bigger ... bigger. It appeared immense. Caution, he told himself, there's an hombre up there with a rifle. He halted, feeling his body weave, and tried to steady himself. High up in the nose of Red Dog the hatch was a dancing black shadow—black with movement. He pulled the rifle from his shoulder and moved the control to full automatic, falling to his knees as he did so. Strange, the ashy floor of the crater was erupting in small fountains just to his side. Danger, he thought, take cover. The warning bells were still ringing in his brain as he slid forward on his stomach and tried to steady his weapon. Dust spurted across his face plate. The black rectangle of the hatch danced crazily in his sights. He pulled back on the trigger, feeling the heavy weapon buck against his shoulder, firing until the clip was empty. His fingers hurriedly searched his belt for the spare clips. Gone. Somehow he'd lost them. He'd have to rush the rocket.

He got to his feet, weaving dizzily, and forced his legs to move. Once or twice he fell, regaining his feet with difficulty.

He heard a voice. It took him a minute to realize it was his own. He was babbling to Prochaska, trying to tell him ...

The sky was black. No, it was white, dazzling white, white with heat, red with flame. He saw Red Dog with difficulty. The rocket was a hotel, complete with room clerk. He laughed inanely. A Single, please. No, I'll only be staying for the night. He fell again. This time it took him longer to regain his feet. He stumbled ... walked ... stumbled. His eyes sought the rocket. It was weaving, swaying back and forth. Foolish, he thought, there was no wind in Crater Arzachel. No air, no wind, no nothing. Nothing but death. Wait, there was someone sitting on top of the rocket—a giant of a man with a long white beard. He watched Crag and smiled. He reached out a hand and beckoned. Crag ran. The sky exploded within his brain, his legs buckled and he felt his face plate smash against the ashy floor. For all eternity, he thought. The blackness came.

Adam Crag opened his eyes. He was lying on his back. Above him the dome of the sky formed a great black canopy sprinkled with brilliant stars. His thoughts, chaotic memories, gradually stabilized and he remembered his mad flight toward Red Dog.

This couldn't be death, he thought. Spirits didn't wear space suits. He sensed movement and twisted his head to one side. Gordon Nagel! The oxygen man's face behind the heavy plate was thin, gaunt, but he was smiling. Crag thought that he had never seen such a wonderful smile. Nagel's lips crinkled into speech:

"I was beginning to wonder when you'd make it." Even his voice was different, Crag thought. The nasal twang was gone. It was soft, mellow, deep with concern. He thought it was the most wonderful sound he had ever heard.

"Thanks, Gordon," he said simply. He spoke the words thinking it was the first time he'd ever addressed the other by his first name.

"How'd you ever locate me?"

"Started early," Nagel said. "I was pretty sure you'd push yourself past the point of no return. You seemed pretty set on getting that critter."

"It's a wonder you located me." He managed to push himself to a sitting position.

"Prochaska didn't think I could. But I did. Matter of fact, I was pretty close to you when you broke from the rocks heading for Red Dog." Red Dog! Crag twisted his head and looked toward the rocket.

"He's lying at the base of the rocket," Nagel said, in answer to his unspoken question. "Your last volley sprayed him."

"Skipper!" Prochaska's voice broke impatiently into his earphones.

"Still alive," Crag answered.

"Yeah—just." Prochaska's voice was peevish. "You were lucky with that last burst of fire."

"Thanks to my good marksmanship," Crag quipped weakly.

"I wish you'd quit acting like a company of Marines and get back here."

"Okay, Colonel."

Prochaska cursed and Crag grinned happily. It was good to be alive, even in Crater Arzachel.

Nagel helped him to his feet and Crag stood for a moment, feeling the strength surge back into his body. He breathed deeply, luxuriating in the plentiful oxygen. Fresh oxygen. Fresh as a maiden's kiss, he thought Oxygen was gold. More than gold. It was life.

"Ready, now?"

"Ready as I ever will be," Crag answered. "Lead on, Gordon."

They had almost reached Bandit when Crag broke the silence. "Why did you come ... to the moon, Gordon?"

Nagel slowed his steps, then stopped and turned.

"Why did you come, Commander?"

"Because ... because ..." Crag floundered. "Because someone had to come," he blurted. "Because I was supposed to be good in my field." His eyes met Nagel's. The oxygen man was smiling, faintly.

"I'm good in mine, too," he said. He chewed at his bottom lip for a moment.

"I could give the same reasons as you," he said finally. "Truthfully, though, there's more to it." He looked at Crag defiantly.

"I was a misfit on earth, Commander. A square peg in a round hole. I had dreams ... dreams, but they were not the dreams of earth. They were dreams of places in which there were no people." He gave an odd half-smile. "Of course I didn't tell the psych doctors that."

"There's plenty I didn't tell 'em, myself," Crag said.

"Commander, you might not understand this but ... I like the moon." He looked away, staring into the bleakness of Arzachel. Crag's eyes followed his. The plain beyond was an ash-filled bowl broken by weird ledges, spires, grotesque rocks. In the distance Backbone Ridge crawled along the floor of the basin, forming its fantastic labyrinths. Yet ... yet there was something fascinating, almost beautiful about the crater. It was the kind of a place a man might cross the gulfs of space to see. Nagel had crossed those gulfs. Yes, he could understand.

"I'll never return to earth," he said, almost dreamily.

"Nonsense."

"Not nonsense, Commander. But I'm not unhappy at the prospect. Do you remember the lines:

Well, that's the way I feel about the moon."

"You'll be happy enough to get back to earth," Crag predicted.

"I won't get back, Commander. Don't want to get back." He turned broodingly toward Bandit.

"Maybe we'd better move on," Crag said gently. "I crave to get out of this suit."