"There's nothing alive," the Captain said at last. "I think we'll go right back; I know most of the crew want to. Get the Government Receiving Station on the sender and tell them what we found, and that we—"

He staggered.

The first atomic shell had struck the ship, spinning it around. The Captain fell to the floor, crashing into the control table. Papers and instruments rained down on him. As he started to his feet the second shell struck. The ceiling cracked open, struts and girders twisted and bent. The ship shuddered, falling suddenly down, then righting itself as automatic controls took over.

The Captain lay on the floor by the smashed control board. In the corner Nasha struggled to free herself from the debris.

Outside the men were already sealing the gaping leaks in the side of the ship, through which the precious air was rushing, dissipating into the void beyond. "Help me!" Dorle was shouting. "Fire over here, wiring ignited." Two men came running. Tance watched helplessly, his eyeglasses broken and bent.

"So there is life here, after all," he said, half to himself. "But how could—"

"Give us a hand," Fomar said, hurrying past. "Give us a hand, we've got to land the ship!"

It was night. A few stars glinted above them, winking through the drifting silt that blew across the surface of the planet.

Dorle peered out, frowning. "What a place to be stuck in." He resumed his work, hammering the bent metal hull of the ship back into place. He was wearing a pressure suit; there were still many small leaks, and radioactive particles from the atmosphere had already found their way into the ship.

Nasha and Fomar were sitting at the table in the control room, pale and solemn, studying the inventory lists.

"Low on carbohydrates," Fomar said. "We can break down the stored fats if we want to, but—"

"I wonder if we could find anything outside." Nasha went to the window. "How uninviting it looks." She paced back and forth, very slender and small, her face dark with fatigue. "What do you suppose an exploring party would find?"

Fomar shrugged. "Not much. Maybe a few weeds growing in cracks here and there. Nothing we could use. Anything that would adapt to this environment would be toxic, lethal."

Nasha paused, rubbing her cheek. There was a deep scratch there, still red and swollen. "Then how do you explain—it? According to your theory the inhabitants must have died in their skins, fried like yams. But who fired on us? Somebody detected us, made a decision, aimed a gun."

"And gauged distance," the Captain said feebly from the cot in the corner. He turned toward them. "That's the part that worries me. The first shell put us out of commission, the second almost destroyed us. They were well aimed, perfectly aimed. We're not such an easy target."

"True." Fomar nodded. "Well, perhaps we'll know the answer before we leave here. What a strange situation! All our reasoning tells us that no life could exist; the whole planet burned dry, the atmosphere itself gone, completely poisoned."

"The gun that fired the projectiles survived," Nasha said. "Why not people?"

"It's not the same. Metal doesn't need air to breathe. Metal doesn't get leukemia from radioactive particles. Metal doesn't need food and water."

There was silence.

"A paradox," Nasha said. "Anyhow, in the morning I think we should send out a search party. And meanwhile we should keep on trying to get the ship in condition for the trip back."

"It'll be days before we can take off," Fomar said. "We should keep every man working here. We can't afford to send out a party."

Nasha smiled a little. "We'll send you in the first party. Maybe you can discover—what was it you were so interested in?"

"Legumes. Edible legumes."

"Maybe you can find some of them. Only—"

"Only what?"

"Only watch out. They fired on us once without even knowing who we were or what we came for. Do you suppose that they fought with each other? Perhaps they couldn't imagine anyone being friendly, under any circumstances. What a strange evolutionary trait, inter-species warfare. Fighting within the race!"

"We'll know in the morning," Fomar said. "Let's get some sleep."

The sun came up chill and austere. The three people, two men and a woman, stepped through the port, dropping down on the hard ground below.

"What a day," Dorle said grumpily. "I said how glad I'd be to walk on firm ground again, but—"

"Come on," Nasha said. "Up beside me. I want to say something to you. Will you excuse us, Tance?"

Tance nodded gloomily. Dorle caught up with Nasha. They walked together, their metal shoes crunching the ground underfoot. Nasha glanced at him.

"Listen. The Captain is dying. No one knows except the two of us. By the end of the day-period of this planet he'll be dead. The shock did something to his heart. He was almost sixty, you know."

Dorle nodded. "That's bad. I have a great deal of respect for him. You will be captain in his place, of course. Since you're vice-captain now—"

"No. I prefer to see someone else lead, perhaps you or Fomar. I've been thinking over the situation and it seems to me that I should declare myself mated to one of you, whichever of you wants to be captain. Then I could devolve the responsibility."

"Well, I don't want to be captain. Let Fomar do it."

Nasha studied him, tall and blond, striding along beside her in his pressure suit. "I'm rather partial to you," she said. "We might try it for a time, at least. But do as you like. Look, we're coming to something."

They stopped walking, letting Tance catch up. In front of them was some sort of a ruined building. Dorle stared around thoughtfully.

"Do you see? This whole place is a natural bowl, a huge valley. See how the rock formations rise up on all sides, protecting the floor. Maybe some of the great blast was deflected here."

They wandered around the ruins, picking up rocks and fragments. "I think this was a farm," Tance said, examining a piece of wood. "This was part of a tower windmill."

"Really?" Nasha took the stick and turned it over. "Interesting. But let's go; we don't have much time."

"Look," Dorle said suddenly. "Off there, a long way off. Isn't that something?" He pointed.

Nasha sucked in her breath. "The white stones."

"What?"

Nasha looked up at Dorle. "The white stones, the great broken teeth. We saw them, the Captain and I, from the control room." She touched Dorle's arm gently. "That's where they fired from. I didn't think we had landed so close."

"What is it?" Tance said, coming up to them. "I'm almost blind without my glasses. What do you see?"

"The city. Where they fired from."

"Oh." All three of them stood together. "Well, let's go," Tance said. "There's no telling what we'll find there." Dorle frowned at him.

"Wait. We don't know what we would be getting into. They must have patrols. They probably have seen us already, for that matter."

"They probably have seen the ship itself," Tance said. "They probably know right now where they can find it, where they can blow it up. So what difference does it make whether we go closer or not?"

"That's true," Nasha said. "If they really want to get us we haven't a chance. We have no armaments at all; you know that."

"I have a hand weapon." Dorle nodded. "Well, let's go on, then. I suppose you're right, Tance."

"But let's stay together," Tance said nervously. "Nasha, you're going too fast."

Nasha looked back. She laughed. "If we expect to get there by nightfall we must go fast."

They reached the outskirts of the city at about the middle of the afternoon. The sun, cold and yellow, hung above them in the colorless sky. Dorle stopped at the top of a ridge overlooking the city.

"Well, there it is. What's left of it."

There was not much left. The huge concrete piers which they had noticed were not piers at all, but the ruined foundations of buildings. They had been baked by the searing heat, baked and charred almost to the ground. Nothing else remained, only this irregular circle of white squares, perhaps four miles in diameter.

Dorle spat in disgust. "More wasted time. A dead skeleton of a city, that's all."

"But it was from here that the firing came," Tance murmured. "Don't forget that."

"And by someone with a good eye and a great deal of experience," Nasha added. "Let's go."

They walked into the city between the ruined buildings. No one spoke. They walked in silence, listening to the echo of their footsteps.

"It's macabre," Dorle muttered. "I've seen ruined cities before but they died of old age, old age and fatigue. This was killed, seared to death. This city didn't die—it was murdered."

"I wonder what the city was called," Nasha said. She turned aside, going up the remains of a stairway from one of the foundations. "Do you think we might find a signpost? Some kind of plaque?"

She peered into the ruins.

"There's nothing there," Dorle said impatiently. "Come on."

"Wait." Nasha bent down, touching a concrete stone. "There's something inscribed on this."

"What is it?" Tance hurried up. He squatted in the dust, running his gloved fingers over the surface of the stone. "Letters, all right." He took a writing stick from the pocket of his pressure suit and copied the inscription on a bit of paper. Dorle glanced over his shoulder. The inscription was:

"That's this city," Nasha said softly. "That was its name."

Tance put the paper in his pocket and they went on. After a time Dorle said, "Nasha, you know, I think we're being watched. But don't look around."

The woman stiffened. "Oh? Why do you say that? Did you see something?"

"No. I can feel it, though. Don't you?"

Nasha smiled a little. "I feel nothing, but perhaps I'm more used to being stared at." She turned her head slightly. "Oh!"

Dorle reached for his hand weapon. "What is it? What do you see?" Tance had stopped dead in his tracks, his mouth half open.

"The gun," Nasha said. "It's the gun."

"Look at the size of it. The size of the thing." Dorle unfastened his hand weapon slowly. "That's it, all right."

The gun was huge. Stark and immense it pointed up at the sky, a mass of steel and glass, set in a huge slab of concrete. Even as they watched the gun moved on its swivel base, whirring underneath. A slim vane turned with the wind, a network of rods atop a high pole.

"It's alive," Nasha whispered. "It's listening to us, watching us."

The gun moved again, this time clockwise. It was mounted so that it could make a full circle. The barrel lowered a trifle, then resumed its original position.

"But who fires it?" Tance said.

Dorle laughed. "No one. No one fires it."

They stared at him. "What do you mean?"

"It fires itself."

They couldn't believe him. Nasha came close to him, frowning, looking up at him. "I don't understand. What do you mean, it fires itself?"

"Watch, I'll show you. Don't move." Dorle picked up a rock from the ground. He hesitated a moment and then tossed the rock high in the air. The rock passed in front of the gun. Instantly the great barrel moved, the vanes contracted.

The rock fell to the ground. The gun paused, then resumed its calm swivel, its slow circling.

"You see," Dorle said, "it noticed the rock, as soon as I threw it up in the air. It's alert to anything that flies or moves above the ground level. Probably it detected us as soon as we entered the gravitational field of the planet. It probably had a bead on us from the start. We don't have a chance. It knows all about the ship. It's just waiting for us to take off again."

"I understand about the rock," Nasha said, nodding. "The gun noticed it, but not us, since we're on the ground, not above. It's only designed to combat objects in the sky. The ship is safe until it takes off again, then the end will come."

"But what's this gun for?" Tance put in. "There's no one alive here. Everyone is dead."

"It's a machine," Dorle said. "A machine that was made to do a job. And it's doing the job. How it survived the blast I don't know. On it goes, waiting for the enemy. Probably they came by air in some sort of projectiles."

"The enemy," Nasha said. "Their own race. It is hard to believe that they really bombed themselves, fired at themselves."

"Well, it's over with. Except right here, where we're standing. This one gun, still alert, ready to kill. It'll go on until it wears out."

"And by that time we'll be dead," Nasha said bitterly.

"There must have been hundreds of guns like this," Dorle murmured. "They must have been used to the sight, guns, weapons, uniforms. Probably they accepted it as a natural thing, part of their lives, like eating and sleeping. An institution, like the church and the state. Men trained to fight, to lead armies, a regular profession. Honored, respected."

Tance was walking slowly toward the gun, peering nearsightedly up at it. "Quite complex, isn't it? All those vanes and tubes. I suppose this is some sort of a telescopic sight." His gloved hand touched the end of a long tube.

Instantly the gun shifted, the barrel retracting. It swung—

"Don't move!" Dorle cried. The barrel swung past them as they stood, rigid and still. For one terrible moment it hesitated over their heads, clicking and whirring, settling into position. Then the sounds died out and the gun became silent.

Tance smiled foolishly inside his helmet. "I must have put my finger over the lens. I'll be more careful." He made his way up onto the circular slab, stepping gingerly behind the body of the gun. He disappeared from view.

"Where did he go?" Nasha said irritably. "He'll get us all killed."

"Tance, come back!" Dorle shouted. "What's the matter with you?"

"In a minute." There was a long silence. At last the archeologist appeared. "I think I've found something. Come up and I'll show you."

"What is it?"

"Dorle, you said the gun was here to keep the enemy off. I think I know why they wanted to keep the enemy off."

They were puzzled.

"I think I've found what the gun is supposed to guard. Come and give me a hand."

"All right," Dorle said abruptly. "Let's go." He seized Nasha's hand. "Come on. Let's see what he's found. I thought something like this might happen when I saw that the gun was—"

"Like what?" Nasha pulled her hand away. "What are you talking about? You act as if you knew what he's found."

"I do." Dorle smiled down at her. "Do you remember the legend that all races have, the myth of the buried treasure, and the dragon, the serpent that watches it, guards it, keeping everyone away?"

She nodded. "Well?"

Dorle pointed up at the gun.

"That," he said, "is the dragon. Come on."

Between the three of them they managed to pull up the steel cover and lay it to one side. Dorle was wet with perspiration when they finished.

"It isn't worth it," he grunted. He stared into the dark yawning hole. "Or is it?"

Nasha clicked on her hand lamp, shining the beam down the stairs. The steps were thick with dust and rubble. At the bottom was a steel door.

"Come on," Tance said excitedly. He started down the stairs. They watched him reach the door and pull hopefully on it without success. "Give a hand!"

"All right." They came gingerly after him. Dorle examined the door. It was bolted shut, locked. There was an inscription on the door but he could not read it.

"Now what?" Nasha said.

Dorle took out his hand weapon. "Stand back. I can't think of any other way." He pressed the switch. The bottom of the door glowed red. Presently it began to crumble. Dorle clicked the weapon off. "I think we can get through. Let's try."

The door came apart easily. In a few minutes they had carried it away in pieces and stacked the pieces on the first step. Then they went on, flashing the light ahead of them.

They were in a vault. Dust lay everywhere, on everything, inches thick. Wood crates lined the walls, huge boxes and crates, packages and containers. Tance looked around curiously, his eyes bright.

"What exactly are all these?" he murmured. "Something valuable, I would think." He picked up a round drum and opened it. A spool fell to the floor, unwinding a black ribbon. He examined it, holding it up to the light.

"Look at this!"

They came around him. "Pictures," Nasha said. "Tiny pictures."

"Records of some kind." Tance closed the spool up in the drum again. "Look, hundreds of drums." He flashed the light around. "And those crates. Let's open one."

Dorle was already prying at the wood. The wood had turned brittle and dry. He managed to pull a section away.

It was a picture. A boy in a blue garment, smiling pleasantly, staring ahead, young and handsome. He seemed almost alive, ready to move toward them in the light of the hand lamp. It was one of them, one of the ruined race, the race that had perished.

For a long time they stared at the picture. At last Dorle replaced the board.

"All these other crates," Nasha said. "More pictures. And these drums. What are in the boxes?"

"This is their treasure," Tance said, almost to himself. "Here are their pictures, their records. Probably all their literature is here, their stories, their myths, their ideas about the universe."

"And their history," Nasha said. "We'll be able to trace their development and find out what it was that made them become what they were."

Dorle was wandering around the vault. "Odd," he murmured. "Even at the end, even after they had begun to fight they still knew, someplace down inside them, that their real treasure was this, their books and pictures, their myths. Even after their big cities and buildings and industries were destroyed they probably hoped to come back and find this. After everything else was gone."

"When we get back home we can agitate for a mission to come here," Tance said. "All this can be loaded up and taken back. We'll be leaving about—"

He stopped.

"Yes," Dorle said dryly. "We'll be leaving about three day-periods from now. We'll fix the ship, then take off. Soon we'll be home, that is, if nothing happens. Like being shot down by that—"

"Oh, stop it!" Nasha said impatiently. "Leave him alone. He's right: all this must be taken back home, sooner or later. We'll have to solve the problem of the gun. We have no choice."

Dorle nodded. "What's your solution, then? As soon as we leave the ground we'll be shot down." His face twisted bitterly. "They've guarded their treasure too well. Instead of being preserved it will lie here until it rots. It serves them right."

"How?"

"Don't you see? This was the only way they knew, building a gun and setting it up to shoot anything that came along. They were so certain that everything was hostile, the enemy, coming to take their possessions away from them. Well, they can keep them."

Nasha was deep in thought, her mind far away. Suddenly she gasped. "Dorle," she said. "What's the matter with us? We have no problem. The gun is no menace at all."

The two men stared at her.

"No menace?" Dorle said. "It's already shot us down once. And as soon as we take off again—"

"Don't you see?" Nasha began to laugh. "The poor foolish gun, it's completely harmless. Even I could deal with it alone."

"You?"

Her eyes were flashing. "With a crowbar. With a hammer or a stick of wood. Let's go back to the ship and load up. Of course we're at its mercy in the air: that's the way it was made. It can fire into the sky, shoot down anything that flies. But that's all! Against something on the ground it has no defenses. Isn't that right?"

Dorle nodded slowly. "The soft underbelly of the dragon. In the legend, the dragon's armor doesn't cover its stomach." He began to laugh. "That's right. That's perfectly right."

"Let's go, then," Nasha said. "Let's get back to the ship. We have work to do here."

It was early the next morning when they reached the ship. During the night the Captain had died, and the crew had ignited his body, according to custom. They had stood solemnly around it until the last ember died. As they were going back to their work the woman and the two men appeared, dirty and tired, still excited.

And presently, from the ship, a line of people came, each carrying something in his hands. The line marched across the gray slag, the eternal expanse of fused metal. When they reached the weapon they all fell on the gun at once, with crowbars, hammers, anything that was heavy and hard.

The telescopic sights shattered into bits. The wiring was pulled out, torn to shreds. The delicate gears were smashed, dented.

Finally the warheads themselves were carried off and the firing pins removed.

The gun was smashed, the great weapon destroyed. The people went down into the vault and examined the treasure. With its metal-armored guardian dead there was no danger any longer. They studied the pictures, the films, the crates of books, the jeweled crowns, the cups, the statues.

At last, as the sun was dipping into the gray mists that drifted across the planet they came back up the stairs again. For a moment they stood around the wrecked gun looking at the unmoving outline of it.

Then they started back to the ship. There was still much work to be done. The ship had been badly hurt, much had been damaged and lost. The important thing was to repair it as quickly as possible, to get it into the air.

With all of them working together it took just five more days to make it spaceworthy.

Nasha stood in the control room, watching the planet fall away behind them. She folded her arms, sitting down on the edge of the table.

"What are you thinking?" Dorle said.

"I? Nothing."

"Are you sure?"

"I was thinking that there must have been a time when this planet was quite different, when there was life on it."

"I suppose there was. It's unfortunate that no ships from our system came this far, but then we had no reason to suspect intelligent life until we saw the fission glow in the sky."

"And then it was too late."

"Not quite too late. After all, their possessions, their music, books, their pictures, all of that will survive. We'll take them home and study them, and they'll change us. We won't be the same afterwards. Their sculpturing, especially. Did you see the one of the great winged creature, without a head or arms? Broken off, I suppose. But those wings— It looked very old. It will change us a great deal."

"When we come back we won't find the gun waiting for us," Nasha said. "Next time it won't be there to shoot us down. We can land and take the treasure, as you call it." She smiled up at Dorle. "You'll lead us back there, as a good captain should."

"Captain?" Dorle grinned. "Then you've decided."

Nasha shrugged. "Fomar argues with me too much. I think, all in all, I really prefer you."

"Then let's go," Dorle said. "Let's go back home."

The ship roared up, flying over the ruins of the city. It turned in a huge arc and then shot off beyond the horizon, heading into outer space.

Down below, in the center of the ruined city, a single half-broken detector vane moved slightly, catching the roar of the ship. The base of the great gun throbbed painfully, straining to turn. After a moment a red warning light flashed on down inside its destroyed works.

And a long way off, a hundred miles from the city, another warning light flashed on, far underground. Automatic relays flew into action. Gears turned, belts whined. On the ground above a section of metal slag slipped back. A ramp appeared.

A moment later a small cart rushed to the surface.

The cart turned toward the city. A second cart appeared behind it. It was loaded with wiring cables. Behind it a third cart came, loaded with telescopic tube sights. And behind came more carts, some with relays, some with firing controls, some with tools and parts, screws and bolts, pins and nuts. The final one contained atomic warheads.

The carts lined up behind the first one, the lead cart. The lead cart started off, across the frozen ground, bumping calmly along, followed by the others. Moving toward the city.

To the damaged gun.