At the rear they set a salvaged engine unit. For steering, they rigged a boom shaft to warp the runners right or left. For cargo, they piled the sled with full containers, ration boxes, the foil tent, what instruments they could detach and carry, armfuls of heat-tools, a crowbar, a hatchet, a few other items.

Moving back from the finished work, one of them stumbled against the other. Instantly the two puffy, soot-black shapes were crouched, gloved fists up, fierce in the system's duskiest corner.

Then the moment passed. Warily, helmets turned toward each other, they went back in the half-stripped wreck.

In the still airtight control room, lighted by one bulb, their officer stirred on his bedstrip. His tunic had been pulled off, his broken left arm and collarbone set and splinted. Under a fillet of bandage, his gaunt young face looked pale, but he had his wits back.

"The appropriate question," he said, "is 'What happened?'"

The two men were removing their helmets. "Conked and crashed, sir," said Jenks, the smaller one, uncovering a sallow, hollow-cheeked face.

Lieutenant Wofforth sat up, supporting himself on his sound arm. "How long have I been out?"

"Maybe forty hours, sir. Delirious. Corbett and me did the best we could. Take it easy, sir," he said as Wofforth began to get up. "Lie back. We've done what Emergency Plan Six says—bolted a sled together and coupled on a sound engine unit for power."

"Quite a haul back to base," said Wofforth, almost cheerfully. His eyes were bright, as though he savored the idea. "About halfway around Pluto. We'd better start now, or they'll get tired of waiting."

"They've gone, sir," Corbett growled before Jenks could gesture him to silence. He was beefy, slit-eyed. "We saw the jets going sunward this morning."

Wofforth winced. "Gone," he said. "That's right. I didn't stop to think. You said forty hours.... They couldn't wait that long. We're past opposition already, getting farther away all the time. They had to go, or they wouldn't have made it."

He stood up uncertainly and reached for his ripped tunic. Corbett stepped over and helped him slide his uninjured arm into the right sleeve, then to fasten and drape the tunic over his splinted left arm and shoulder.

"We'll just have to get back to Base Camp and wait," said Wofforth grimly.

"Sir," said Jenks, "our radio is gone. I tried to patch it up, but it was gone. When they didn't get a signal, they must have thought—"

"Nonsense!" Wofforth broke in. "They'll have left us supplies. They couldn't wait, signal or none. Our job is to get back, and stick it out there until they come for us."

He sat at the control and began to write in the log book. Corbett and Jenks drifted together at the other end of the room.

"You meat-head," snarled Jenks under his breath. "You knew he took the berth to Pluto because the first mate was a lady—Lya Stromminger."

"He had to know they were gone," protested Corbett, equally fierce.

"Not flat like you gave it. He came here to be with her. Now she's jetted away without him. How does a man feel when a woman's done that—"

"Stop blathering, you two, and help me into my suit," called Wofforth, rising again. "We're going to rev up that sled engine and get out of here!"

Outside, the sled lay ready under the frigid sky. Wofforth tramped around it, leaned over and poked the load.

"Too much," said his voice in their radios. "Keep the synthesizer, the tent, these two ration boxes. Wait, keep the crowbar and the hatchet. Dump the rest."

"We travel that light, sir?" said Jenks doubtfully.

"I've been figuring," said Wofforth. "We're on the far side of Pluto from Base Camp. That makes ten thousand miles, more or less. Pluto's day is nineteen hours and a minute or so, Earth time. We can travel only by what they humorously call daylight. And we'd better get there in ten days—a thousand miles every nine and a half hours—or maybe we won't get there at all."

"How's that, sir?" asked Corbett.

"The heaters in these suits," Wofforth reminded him. "Two hundred and forty hours of efficiency, and that's all. Well, it's noon. Let's take off."

His voice shook. He was still weak. Jenks helped him sit on the two lashed ration boxes, and slung a mooring strap across his knees. Then Jenks took the steering boom, and Corbett bent to start the engine.

When the arclight sun set in the west, they had traveled more than four hours over country not too rugged to slow them much. Darkness closed in fast while Jenks and Corbett pitched the pyramidal tent of metal foil and clamped it down solidly. They spread and zipped in the ground fabric, set up lights and heater inside, and began to pipe in thawed gases from the drifts outside.

After their scanty meal, Corbett and Jenks sought their bedstrips, on opposite sides of the tent. Wofforth tended the atomic heater for minutes, until the sound of deep breathing told him that his companions were asleep.

Then he put on his spacesuit, clumsy with his single hand to close seams. He picked up sextant and telescope, and slipped out into the Plutonian night.

It was as utterly black as the bottom of a pond of ink. But above Wofforth shone the faithful stars, in the constellations mapped by the first star-gazers of long ago. He made observations, checked for time and position. He chuckled inside his helmet, as though congratulating himself. Back in the tent, he opened the log book and wrote:

Wriggling out of his space gear, he lay down, asleep almost before his weary limbs relaxed.

Everyone was awake before dawn. They made coffee on the heater, and broke out protein biscuits for breakfast.

As the tiny sun winked into view over the horizon, they loaded the sled. Corbett slouched toward the idling engine at the tail of the sled.

"No, get on amidships," said Wofforth. "I'll take over engine."

"My job—" began Corbett.

"You're relieved. Strap yourself on the ration boxes. That's right. Jenks, steer again. Make for the level ahead."

With his right hand Wofforth ran a length of pliable cable around his waist and through a ring-bolt on the decking. He touched the engine controls, and they pulled away from camp.

The sled coursed over great knoll-like swellings of the terrain, coated with the dull-pale frozen atmosphere. Beyond, it gained speed on a vast flat plain, almost as smooth as a desert of glass.

"What's this big rink. Lieutenant?" asked Jenks.

"Maybe a sea, or maybe just a sunken area, full of solid gases. Stand by the helm, I'm going to gun a few more M. P. H. out of her."

"No wind," grunted Corbett. "Nothing moving except us. The floor of hell."

"If you was in hell, the rest of us would be better off," said Jenks sourly.

Wofforth began to sing, though he did not feel like it:

At camp that night he wrote in the log book:

"What's for supper?" bawled Corbett, entering. "I could eat a horse."

"That'd be cannibalism," said Jenks at once.

"Yah, you splinter! Don't eat any lizards, then."

Spirits good, Wofforth corrected his entry, and closed the log book. He thought of Lya Stromminger. She was a most efficient officer. Her hair was black as night on Pluto, and her eyes as bright as the faraway sun.

Wofforth wrote in his log book:

He wrote in his log book:

He wrote in his log book:

"Lieutenant," said Jenks from across the tent, as Wofforth closed the book.

"Well?"

"We know you're in command. This party and all of Pluto. But we ask permission to state our case."

"What case is your case?" demanded Wofforth, rising. "I'm doing my best to get you back to Base Camp."

"Sure," said Corbett. "Sure. But why Base Camp?"

"You know why."

"That's right, we know why," agreed Jenks, and Corbett grinned in his ten days' tussock of beard.

"They'll have left supplies for us," Wofforth went on. "Shelter and food and fuel and instruments. They'll expect us to reach Base Camp and hold it down for the next attempt to reach Pluto."

"We know why," repeated Jenks. "And that's not why, lieutenant. Let me talk, sir. It's a dead man talking."

"You won't die," snapped Wofforth. "I'll get you both there alive."

He stepped to where, in one corner, he had managed a bath—a hollow in the frozen ground, lined by pushing the floor fabric into it. From the heater he ran tepid, clean water into it. He clipped a mirror to the tent foil, searched out an automatic razor, and began to shave his own dark young thatch of beard.

"You're proving my point, lieutenant," said Jenks. "Policing up your face to look pretty."

"Why not?" growled Wofforth, mowing another swath of whiskers.

"No reason why not. Ten, twenty years from now they'll find your body—whenever the inner orbits get to where they can boom off another expedition. You'll look young and clean-shaved. You know who'll weep."

Wofforth lowered the razor in his good hand and glared at the two. They grinned in the bright light opposite him. They looked as if they hoped he'd see the joke.

"I said it's a dying man that's talking," said Jenks again. "Won't you let me say my dying say, lieutenant? Let's all die honest."

"I'm going to get you there," Wofforth insisted.

"Ah, now," said Corbett, as though persuading a naughty child. "You think they've left twenty years' worth of supplies to keep us going? The ship didn't carry that much, even if they left it all." He grinned mirthlessly. "I can figure what you're figuring, lieutenant," he went on, with a touch of Jenks' sly manner. "You die, young and brave. You'll shave up again before you lie down and let go. And when the next shipload arrives there'll be you, lying like a statue of your good-looking young self, frozen stiff. Am I right?"

Corbett was right, Wofforth admitted to himself. The man was more than a great meaty lump, after all, to see another man's unspoken thought so clearly.

"Then," Jenks took it up, "First Mate Lya Stromminger will have a look. She may command the new expedition. She'll be promoted away up to Admiral or higher—twenty years of brilliant service—gone gray around the edges, but still a lovely lady. There you'll lie before her eyes, young and brave as you was when she deserted you. She'll cry, won't she? And hot tears can't thaw you out or wake you up—"

"Shut your heads, both of you!" shouted Wofforth, so fierce and loud that the foil tent wall vibrated as with a gale in the airless night.

But they had guessed true. He'd wanted to be found at Base Camp. He'd wanted Lya Stromminger to know, some day, that she'd blasted off and left behind the man most worthy of all men on all worlds....

"Everybody takes a hot bath tonight," said Wofforth. "We'll all sleep better for it. Tomorrow's our last day on the trail."

"To do two thousand miles?" said Jenks.

"To do all of that. The expedition mapped an area at least that wide around Base Camp, and it's slick and smooth. We can almost slide in."

"All slick and smooth but just this side of Base Camp, lieutenant," said Jenks.

"How do you mean?"

"That string of craters. Don't you remember? It's just this side—east of Base Camp. This sled'll never go over that, sir."

"Nor around," Corbett put in. "We'd have to detour maybe three thousand miles. And the heaters in our suits won't last."

"I know about the craters," said Wofforth. "Well take care of them when we reach them."

Stripping, he lowered his body into the makeshift tub and began to scrub himself one-handed.

He wakened in the morning to the sound of furious argument.

Corbett and Jenks, of course. A trifle—division of the breakfast ration, or of the breakfast chores—had set off their nerves like trains of explosive. Even as Wofforth rose from his bedstrip, Corbett swung a cobble-like fist at Jenks' gaunt, grimacing face. The nimbler, smaller man ducked and sidled away. Corbett took a lumbering step to close in on his enemy, and Jenks darted a hand to his belt behind, then brought it forward again with an electro-automatic pistol.

"I've been keeping this for you!" Jenks shrilled. "I'll just diminish the population of Pluto by thirty-three and one-third percent!"

"Hold it!" bellowed Wofforth.

He was too late. A stream of bullets chattered through Corbett's body, folding him over and ripping through the paper-thin wall of the tent. Air whistled out; the tent began to collapse.

Jenks, pinned under Corbett's body, was squealing like a pig. "Lieutenant, help me—!"

Wofforth saw in an instant that the wall could not be patched in time; the bullets had torn loose an irregular strip, pressure had done the rest: even now, the tent was only a few seconds away from complete collapse. As he stumbled across the floor toward the spacesuits, his heart was laboring and his chest straining for breath. Spots swam in front of his eyes. He found the topmost spacesuit by touch, and fumbled for the helmet. The tent drifted down on his head in soft, murderous folds. He opened the valve, shoved his face into the helmet, and gulped precious oxygen. His dulled awareness brightened again, momentarily; but he knew he was still a dead man unless he could get into the suit before pressure fell completely. Numbed fingers plucked at the suit opening. Somehow he got the awkward garment over his legs, closed and locked the torso, pulled down the helmet....

He was lying in darkness, with a low, steady hiss of oxygen in his ears. He rolled over weakly, got to his feet. He turned on his helmet light. He was propping up a gray cave of metal foil, that fell in stiff creases all around him. At his feet were the bodies of Jenks and Corbett. Both were dead.

After a while, clumsily, painfully, he dragged the two corpses free of the tent. He found the heater and thawed a hole in the frozen surface, big enough for both. He tumbled them in, then undercut the edges of the hole with the heater, so that chunks fell in and covered them. While he watched, the cloud of vapor he had made began to settle, slowly congealing on the broken surface and blurring it over again. In a year, there would be no mark here to show that the surface had been disturbed. In a thousand years, it would still be the same.

In the first ray of dawn he flung all supplies from the sled except the fuel containers. He checked the engine, and started it.

Into his belt-bag he thrust the log book. Nothing else went aboard the sled—no food, no water container, no tools, instruments or oxygen tanks. The tent he left lying there, with all that had been carried inside the night before.

As the sun rose clear of the distant rim of the plain to eastward, he rigged a line to the steering boom, then lashed himself securely within reach of the engine. Steering by the taut line, he started westward, slowly at first, then faster. It was as he had hoped. The lightened sled attained and held a greater speed than on any previous day.

"I'll make it," he said aloud, with nobody else to listen on all Pluto. "I'll make it!"

Faster he urged the engine's rhythm, and faster. He clocked its speed by the indicators on the housing. A hundred and fifty miles an hour. A hundred and sixty; not enough. Whipping the boom line tight around his waist to hold his course steady, he sighted between the upcurve of the runner forward. There was level, smooth-frozen country, mile upon mile. He speeded up to one hundred and seventy-five miles an hour. More. The sled hummed at every joining.

At noon, he had done a good thousand miles. At mid-afternoon, sixteen hundred. Two and a half hours of visibility left, and more than four hundred miles to go.

"I can do those on my head," muttered Wofforth to himself, and then, far in the distance, the flat rim of the horizon was flat no longer.

It had sprung up jagged, full of points and bulges. Speeding toward it, he steered by the line around his waist while he cut his engine. He came close at fifty miles an hour, almost a crawl.

Some ancient volcanic action had thrown up those mountains, like a rank of close-drawn sentries. The sled could not cross them anywhere. Still reducing speed, Wofforth drew close to a notch, but the notch gave into a crater, a great shallow saucer two miles in diameter and filled with shadows below, so that Wofforth could not gauge its depth. Opposite, another notch—perhaps once the crater had been a lake, with water running in and out. If he had come there at noon, he could have seen the bottom, and perhaps—

"But it isn't noon." Wofforth was talking to himself again. His voice sounded thin and petulant in his own ears. "By noon tomorrow, the heat will be out of this suit."

He stopped the sled, unlashed himself and trudged to the notch. He stood in it, looking down, then across.

The little bright jewel of the sun, sagging toward the horizon, showed him the upper reaches of the crater's interior, pitched at an angle of perhaps fifty degrees.

Even if it had been noon, it would have been no use. The sled could never climb a slope like that.

Then he looked again, this way and that. He nodded inside his helmet.

He might as well try.

Returning to the sled, he started the engine and lashed himself fast again. He steered away from the crater, and around. He made a great looping journey of twenty miles or so across the plain, building speed all the time.

As he rounded the rear curve of his course, he was driving along at two hundred and sixty miles an hour, and he had to apply pressure to the boom with both hand and knees to point the sled back straight for the notch. Straightening his humming vehicle into a headlong course, he leaned forward and sighted between the upcurved runners.

"Now!" he urged himself, and watched the break in the crater wall rush toward him.

It greatened, yawned. He leaped through, and with a groaning gasp of prayer he dragged the boom over to steer the sled right.

It worked, as he had not dared hope. The runners bounced, bit. Then he was racing around the inside of the great cup's rim, like a hurtling bubble on the inner surface of a whirlpool's funnel. Two miles across, three miles and more on the half diameter—the engine laboring up to three hundred miles an hour, centrifugal force holding it there—

Little more than thirty seconds raced by when he knew he had won. He saw the far notch growing near. He came to it in a last booming rush, and hurled his whole weight against the boom to face the runners into the notch.

Under the low-dropping sun, he and his sled shot into open country beyond the range.

His right arm felt dead from shoulder to fingertip. His head roared and drummed with the racing of his blood. His face had tired spots in it, where muscles he had never used before had locked into an agonized grimace.

On he sped, straight west, gasping and gurgling and mumbling in crazy triumph.

An hour, an anticlimactic hour wherein the sled almost steered itself over the smoothest of plain, and up ahead he spied the black outline of Base Camp.

It was a sprawling, low structure, prefabricated metal and plastic and insulation, black outside to gather what heat might come from outer space. It held aloof on the dull frozen plain from the irregular stain where the expedition ship had braked off with one set of rockets and had soared away with another set. Larger, more familiar, grew Base Camp with each second of approach. Shakily Wofforth cut his engine, slowed from high speed to medium, to a hundred miles an hour, to sixty, to fifty. He made a final circle around Base Camp, and let it coast in with the engine off, to within twenty yards of the main lock panel.

He got up, on legs that shook inside his boots. He felt his heart still racing, his head still ringing. He sighed once, and walked close, his gauntlet fumbling at the release button on the lock panel.

But the button did not respond.

"Jammed," he said. "No—locked."

He couldn't get in. He had reached Base Camp, but he could not get in. They hadn't counted on his return. They'd gone off and left Base Camp locked up.

He sagged against the lock panel, and cursed once, with an utter and furious resignation.

He felt himself slipping. He was going to faint. His legs would not hold him up. He was slipping forward—seemed to be sinking into the massive and unyielding outer surface of Base Camp. It was a dream. Or it was death.

He did not lose all hold on his awareness. He had a sense of lying at full length, and blinding light flashes that made his eyelids jump. And a tug somewhere, as though his helmet was coming off. He would have put out a hand to see, but his left arm was broken, and his right arm limp from weariness.

"You're back," said a voice he knew, a voice strained with wonder. "You managed. I knew you would."

"Now," said Wofforth, "I know it's a dream. We dream after we die."

A hand was cupped behind his neck, lifting him to a sitting position. He felt warm fluid at his lips. "It's no dream," said the voice beseechingly. "Look at me."

"I don't dare. The dream will go away."

But he opened his eyes and looked at her hair like Plutonian night, her eyes like bright stars. "Lya," he said. "I'm going to call you Lya."

"Please call me Lya."

"I'd be bound to dream about you. I've dreamed about you so much.... Owww!"

He got his right hand up to cherish his tingling cheek.

"So you felt that," she said. "Now you know you're awake. Or must I slap you again?"

"I'm sorry, Madame."

"You called me Lya. Can you stand up? I'll help you."

She helped him. He stood up, there in the admission chamber of Base Camp. Lya Stromminger was smiling, and she was crying, too.

"You didn't go away," he said. "You're still here." The weight of his odyssey, half around Pluto, was beginning to stagger him.

"No, I stayed. I knew you'd come back. I knew Pluto couldn't kill you or keep you from coming back."

He drank more from the cup she held to his lips.

"We'll wait together for them to come with the next expedition," she promised him.

"Twenty years? Supplies—"

"There'll be plenty. Don't you know about Pluto? Didn't those craters, those old volcanoes, tell you?"

Thinking of how he had crossed the crater, Wofforth shuddered.

"Pluto is colder than anybody even guessed—outside. But inside are the internal fires—like all the solid planets. We made our tests and we can tap them. I kept the instruments for that. It means we'll have power, and can make our synthetic foods and so on for as long as we need them. You are I are the inhabitants here—"

He stumbled to a chair and sat. "Twenty years—" he said.

Her arm was still around him. Her hair brushed his cheek. "It won't be long. We have so much to say to each other."