A CODE FOR SAM, by Lester del Rey

Originally published in If, November 1966.

I

It was hours after the cave-in before the first sounds of rescue reached Sam. He switched his brain back to high amperage drain to come fully alert and began sending more current through his body heaters to prepare for emergence. From the nearness of the digging, there could be only a few feet of rubble left in the collapsed tunnel.

Fifteen minutes later, he felt a pick strike near his outstretched hand. He grabbed it and pulled himself out of the dirt and gravel around him, then scrambled quickly forward to the entrance. Surprisingly, it was a human hand that reached out to help him to his feet.

“You okay, Sam?” Barney Collins asked. The wizened old prospector’s face and oxygen mask were filthy with sweat and dust, but concern showed plainly in his eyes.

Sam nodded. “I’m fine, Barney. What happened to Pete?”

“The new robot?” Barney shoved his mask aside and spat out tobacco juice, then shrugged. “Something funny about him. Came into camp hours ago, but never said a word about you till we got worried and asked. Come on, we better get back in the digger before it gets colder.”

Sam glanced about, to see that the day was almost done. The high ceremonial mounds were casting long shadows as Tau Ceti sank in the east, and the thin air was already losing heat. In another hour, the temperature would be forty below zero. At its best, Anubis was a hostile world even to a robot like Sam, totally unlike the lovely second planet men called Isis. Here, except for the Gregg Archeological Expedition, there were only a few prospectors and trappers, with a small spaceport and trading post at Ramses to service them.

Their digger was a converted prospector tank with a larger cabin and a collapsible shovel crane on top. Inside, Barney threw off his mask and began washing it hastily, while Sam lifted his chestplate and switched to freshly charged batteries. The man turned on the headlight, then swung the vehicle on its caterpillar treads to head back toward the camp, some four miles away.

“A lot of trolls showing up,” he muttered. “Too blamed many.”

* * * *

A dozen natives could be seen in the headlight beams as he spoke, moving aside to let the digger pass. Their snarling, vulpine faces stared fixedly at the machine. They stood three feet high, with bodies like pears mounted on pipestem legs and with arms that nearly touched the ground. A greenish fur stood out several inches as insulation against the cold. All were armed with spears and heavy stone hammers, and some had bows slung over their backs. There were no young among them.

Sam shared none of Barney’s prejudice against the trolls, but he felt a growing unease as they passed another armed group. In the years he had worked with Gregg to untangle the lost past of Anubis, he had encountered no real threat from them. But their sullen legends were full of violence, and most of it centered here at the Burial Mounds of the Rock Devils where the expedition was digging.

The men were just sitting down to eat as they entered the main expedition Quonset. Barney took his seat between the gray form of James Gregg and the heavy figure of his former prospecting partner, Yeng Lee. Across the table, young Dickson sat alone. He had joined them with the PT model robot two days before, unasked but bearing authorization from the Earth university that was funding them. The space he’d taken in the supply truck hadn’t made him any more welcome. And now his face was flushed with heat from some argument that had been going on before Sam arrived.

Gregg motioned for Sam to take one of the chairs. “All right, now maybe we’ll get some sense out of it. Sam, what happened to you? Dickson here won’t let me question Pete properly.”

“I have every authority to retain full control over Pete, as you know, Dr. Gregg,” Dickson said in a tone he tried to keep patient. He had moved away slightly as Sam dropped beside him, a gesture that betrayed his Earth origin even more than his accent. “Pete is an important experimental model. I cannot let him be ruined by improper handling.”

Sam broke in quickly to tell what he could, but he wasn’t entirely sure himself. He’d been digging a tunnel into the core of a new mound after instructing Pete in the placement of temporary shoring. There had been the sound of strain on one section, and he’d yelled for Pete to get under it and support it until new bracing could be added. Then the whole roof came down, trapping him.

“The cave-in may have started before Pete could reach it,” Sam finished. He didn’t believe it, but his back had been turned at the time. “But Jim, I—”

Gregg interrupted impatiently. “All right, we’ll let that go. But I want to know why he abandoned you there and then didn’t report when he got back! Well, Dr. Dickson?”

“I won’t even discuss it before another robot,” Dickson said.

Gregg’s fist hit the table with a blow that made the dishes jump. “By Horus, Dickson, one more crack like that and you’ll be walking back to Ramses, fund or no fund! Sam’s my second-in-command here, as well as a friend of mine. Pete, come out here!”

“Easy, Jim,” Barney said quietly. “The kid’s from Earth and doesn’t know any better. Give him time.”

Gregg’s face lost some of its tenseness. He fumbled in his pocket and dragged out a cigarette, tapping it sharply against the table. He was just lighting it when Pete emerged from the kitchen.

Then the new robot was across the main room at a single leap, and his fingers were tearing the cigarette out of Gregg’s mouth. He dropped it onto the packed dirt floor and ground it out with his heel.

“Cigarettes are harmful to human beings, Master,” he said in his gentle, monotonous voice.

II

Dickson had jumped to his feet and covered the robot’s body with his own before Gregg could push up from the chair. Now he began shoving Pete from the room, saying something in words too low for the others to hear. Then he was back, looking acutely embarrassed.

“I’m sorry—very sorry. He won’t do that again. I’ve told him that cigarettes are only harmful on Earth—quite healthful here.” He sighed and groped backwards for his chair. “I—I guess I’d better explain, even though it may contaminate our experiment.”

Gregg took a long time lighting another cigarette. Finally he nodded stiffly. “Yes, Dr. Dickson, I think perhaps you’d better.”

Dickson began awkwardly with needless background and too much bias. Robots were produced by Earth companies and leased from them, but nearly all were used in space, where they could cope with hostile environments better than men. As a result, most Earthmen had never seen a robot, and inexperience left them prey to every fantasy from the ancient horror films. And, of course, occasionally a robot did injure a human, with sensational headlines in all Earth newspapers.

“So we had to make robots safe for Earth,” Dickson went on. “To do that, we had to devise a foolproof code of ethics for them.”

“Maybe you’d better find a decent code of ethics for humans and use that,” Barney suggested.

Dickson smiled dutifully. “It wouldn’t work. Men’s ethics revolve around instinctual social drives; but robot brains contain only what is put into them during their education programs. Hence we must have precise rules that can be completely conditioned into them. Fortunately, I was able to discover such laws in the same literature which enabled Dr. Sorrenson to discover our faster-than-light drive.”

They might have guessed it. After Sorrenson invented the space drive and publicly admitted he’d taken the idea from an old science-fiction story, a lot of the borderline sciences had leaped onto the bandwagon. Nobody had yet found anything else useful, but it was a good way to get research money now.

* * * *

“Good Lord!” The anger on Gregg’s face had been replaced by a growing amazement. “The three laws of the Asenion robots! I read about them up in my grandfather’s attic when I was a kid. Don’t tell me you took those plot tricks seriously?” He closed his eyes, trying to remember. “A robot must not inflict or permit harm to a human; subject to that law, a robot must obey human orders; and subject to both laws, a robot must protect itself. Right?”

“Not precisely. But in general—”

“Slavery and racism!” Lee spat the words out. “A black slave must not strike a white master; a black slave must obey a white master’s orders; a black slave must protect itself as part of its white master’s property. You call that ethics?”

“I don’t think the author meant them that way, Lee. They were just things he could build plots on, for fun,” Gregg said.

The big man grimaced. “Fun! I suppose having Pete call every human Master is an Earthman’s idea of fun, too?”

“Unfortunately, it probably is.” Gregg turned back to Dickson, and his face was completely sober. “Naturally, you had to train Pete to be as literal minded as most of the fictional robots. Any flexibility or judgment would have ruined your precious code. Poor Pete! Without human orders, he had to run away from any danger in the tunnel to protect himself. The robot Sam meant nothing in his code. And then, because he probably knew he’d done something wrong, he had to protect himself further by making no report until ordered to do so. Give him a month of normal work in conflict with your code, and Pete’s going to be hopelessly insane—maybe dangerously so. Dr. Dickson, your experiment’s finished. Until you can leave, you’ll keep Pete under close supervision, confined to the kitchen.”

“No!” Sam put a heavy hand on Dickson’s shoulder and shoved the white-faced man back into his chair before angry words could spill from his lips. “No, I’m going to need Pete in the new tunnel tomorrow. And I’ll need Dr. Dickson to make him obey my orders.”

Gregg shook his head. “Impossible. Sam, you don’t know what you’d be letting yourself in for.”

“Then I’ll have to risk it. No, wait. You were all so busy arguing about Pete’s ethics that I never got a chance to finish my report. Jim, this isn’t like the tunnels we’ve dug through all the other mounds. It’s—”

“King Tut’s Tomb!”

Sam nodded. “Maybe. At least I’ve struck against some kind of a metal barrier less than half way through the mound.”

Then the men were clustering around him, pounding him on the back and yelling for the few details he could give. Even Dickson began to catch the feeling, though his eyes kept darting back to the metal hand that had rested so rudely on his shoulder.

Later, when the men had finally retired to their bunks, Sam had time to let the contagion of their enthusiasm drain away and to get back to his private doubts. He moved out into the freezing night, staring at the ring of eyes around the Quonset. The trolls were still gathering here, armed and waiting. As he watched, a new group moved up and found places to huddle, only few hundred yards from the camp.

Fifteen years, he thought as he went back into the dim main room. Long years while Gregg and he tracked down tiny bits of evidence that seemed to indicate the trolls had somehow reached a brief period of high culture a thousand years before. A worn bit of metal knife blade; a chipped burning glass that still worked; the divergent legends of the Killing of the Rock Devil and the yearly ceremony of mound building. And then the final discovery.

Lee and Barney, returning from prospecting, had found a battered metal object sticking out of one mound. They hadn’t considered it important enough to mark the mound, but they’d taken it to Gregg at Ram. When finally opened, it contained nearly two hundred well preserved sheets of paperlike material covered with writing.

Sam took out a set of photocopies and glanced through it. A primitive language changes slowly, and the decoded writing was a phonetic script for early troll speech. He could read most of it now without Gregg’s dictionary or notes. But he couldn’t accept it.

Without leaving evidence of a technology capable of building huge telescopes, how could any culture write a simplified text on astronomy that described the various galaxies and the evolution of stars? How could such a culture refine and alloy aluminum and then roll it out to make the flat sheet that formed a barrier in the tunnel?

If the ancestors of the trolls had achieved all that once, who could hope to guess what they might do now?

On impulse, Sam carried the photocopy back into the kitchen where Pete was still sitting. There was time enough before morning for a PT robot to master Old Trollish, and the ability might prove useful later. At least it would fill Pete’s time better than brooding about his code of ethics.

III

In the morning, the trolls seemed to have filled the whole area. They made no hostile move as the expedition party began unloading the digger and carrying shoring supplies up to the tunnel, but hundreds of eyes followed every move.

Gregg had been conferring with a couple of old trolls he had recognized, but now that conference seemed to be over. He was staring into the tunnel mouth cautiously as Sam and Pete climbed up to it with a load of shoring. He slipped the flashlight off its hook and began crawling forward, obviously trying to catch a glimpse of the other end. Pete watched intently until the man was nearly inside the entrance. Then he dropped the last of his load and dashed forward to drag Gregg back.

“You might be hurt, Master. It isn’t safe in there,” he warned the man gently.

Surprisingly, Gregg grinned slightly. “Oh hell, maybe you’re right this time, Pete. Go back to work, and I’ll behave.”

He waited until he was alone with Sam and then gestured toward the tunnel. “You’re going to need a lot more material than we brought to shore that up safely. The whole mound above it looks unstable. Think you can make out all right while we pull material out of Lee’s last dig?”

“I think so,” Sam told him. “So far, Dickson’s lecture to Pete about following my orders seems to work. What about the trolls?”

“They’ve been hearing rumors that we’re trying to bring the Rock Devil back to life, near as I can make out. I’ve told them we just want to make sure he’s still dead and really kill him if not. They seem willing to accept that, but they’re going to stick around to make sure.” He shrugged. “Maybe I’d better leave Dickson with you and Pete. He’s not much good for work, anyhow.”

He slipped over the edge and slid to the surface below. A few minutes later, the digger took off, drawing a small contingent of trolls after it. Most stayed on, keeping their gaze fixed on Dickson and the robot.

There wasn’t much Dickson could do. He found a broad rock near the supplies and sat watching as Sam and Pete drew on their grappling mittens and heaved and pulled the heavy sections of wire mesh up to the ledge in front of the tunnel. Finally the work of hauling was finished.

“You go first, Pete,” Sam ordered. “I’ll back you up.”

Pete considered the tunnel and began drawing back from it. “I can’t. Yesterday proved that it’s too dangerous in there.”

Dickson was running toward them, and Pete would follow his orders, of course; the second law took precedence over the third. But Sam had taken enough nonsense. He couldn’t depend on calling Dickson to intercede if an accident happened in the tunnel.

He stepped forward, brushing Pete’s hesitant arms aside with a savage thrust. His grappling mittens closed firmly over the robot’s neck, and he began forcing the claws of the mittens together.

“You’re in more danger now than you would be in the tunnel,” he told Pete. “You’ll have every wire in your neck short-circuited, unless you make up your mind to obey my orders from now on.”

Pete’s head bobbed as far as it would go. “Yes, Master.”

“I’m not your master. I’m just Sam.”

“Yes, Sam. I’ll go in the tunnel and do what you order.”

“Sam, stop it!” Dickson was screaming and struggling to break Sam’s grip. “Release him at once, Sam. That’s an order!”

Sam let his grip loosen and shoved the man aside. “You’d better get back below, Dr. Dickson. I don’t have a second law—maybe not even a first one. If I’ve got any code at all, you wouldn’t know it—because it wouldn’t occur to you to ask a normal robot about such things as ethics, would it?”

The brief flush of fright was fading from Dickson’s face, to be replaced by a thin smile. “No,” he admitted. “It really didn’t occur to me. Perhaps I should ask you, some time when we’re both not so busy. I’m sure you’d have an interesting answer.”

Enlarging and bracing the tunnel was hard, slow work. Pete was no longer affected by the risk, but he was sadly lacking in initiative. After the first few minutes, Sam took the lead position, letting the other robot haul rubble and fetch supplies. By the time the men came back, less than twenty feet had been braced and lined properly with canvas and mesh.

There was room for no more than two in the tunnel, and the robots were better suited than the men for such work. Barney and Lee stayed near the entrance, hauling back baskets of rubble, while Gregg operated the digger shovel occasionally to clear the ledge. The cave-in seemed to have loosened part of the mound above them, and the work became increasingly difficult as they moved further in. It was long after noon before the last section was cleared, to expose a six-foot circle of what seemed to be machine-rolled aluminum sheet that blocked further progress.

Gregg came down to inspect it, tapping the metal doubtfully. “Sounds hollow, and not very thick. Can you cut it?”

“There may be danger for you, Master,” Pete warned hesitantly.

Gregg sighed, but stepped back. “All right. I’ll keep my oxygen mask tight. Go ahead, Sam, open it!”

If the metal had ever been tempered or work-hardened, time had softened it. While Pete held the light, Sam began cutting it with the mesh nips. He tore the last few feet out and folded the panel back against the tunnel wall.

All the men were crowded into the tunnel by the time he had finished, pressing forward and craning their necks to see what lay beyond. But they waited impatiently while Sam found a place inside for the light and Gregg took the necessary photographs for the record.

Metal walls and roof formed a low dome, not more than twenty feet in diameter. A battered, dented door at one side was flanked by benches that curved along the walls. Opposite the door, hanging shelves rose to a height of six feet. The largest feature of the room was directly in front of those—an enclosed table or desk, with a seat attached to it on a swinging arm. The floor was of metal, strewn with wreckage and damaged machinery.

Sam’s eyes swung rapidly over the scene and then centered on the objects scattered across the shelves and spilled onto the floor below. There were dozens of familiar metal containers and other things that could only be books.

He was across the room as soon us the camera stopped clicking, reaching out cautiously for them. Beside him, he heard Gregg’s breathing catch. He half expected the book to crumble at his touch, but whatever the paperlike material was seemed proof against time. There was a solid feel to the book and the pages turned easily.

The characters were the same as those of Old Trollish, with two new additions. But the words were totally meaningless.

“Aliens,” Gregg said. “They had to be. There isn’t a thing in this room designed to fit troll hands or bodies. Let’s take a look at the canisters.”

* * * *

Once it was pointed out, the un-trollish nature of everything was obvious. Even the door handle was too high. A man or robot might have sat at the desk Pete and Dickson were inspecting, but no troll could have used the swinging seat.

“Trolls maybe didn’t design any of this, but they sure ruined it,” Barney called. “Better take a look at this, Jim.”

He and Lee had gone at once to examine the wrecked machinery. Now he began pointing out what they had discovered.

The largest piece was obviously some kind of organic fuel cell, with the piping around it reduced to twisted metal shreds. Something with vats and movable flat belts might have been either the source of the plastic paper or a way of printing on it—or both; there wasn’t enough left to be sure. And a beautifully simple typewheel writing machine was intact, except for its motor. Half a dozen broken stone axe heads could be seen to show what had caused the damage.

“Looks like they started a news press here, and vox pop didn’t like the truth,” Barney said bitterly, “Every blamed thing that moved is smashed to smithereens.”

Gregg nodded thoughtfully. “Well, get what details you can with the camera.” He motioned to Dickson, who was watching Pete try to pry open a locked desk drawer. “Give them a hand moving things, will you? I want to find out if there’s any information in those canisters.”

The containers opened easily to pressure in the right places, and this time the writing was in Trollish. Sam found a text on agriculture, one on metallurgy, and a duplicate of that on astronomy. Then the fourth came open, and he let out a cry for Gregg.

There were two columns this time, one in Trollish and the other in what must be alien words. They flipped through the pages, finding another section with the order reversed. It was obviously a bilingual dictionary, alphabetized for both languages, and covering several thousand words. Two other complete sets of sheets lay behind the first.

“What a Rosetta Stone!” Gregg exulted. He was literally caressing the sheets. “And in triplicate! With this, we’ll be reading all those books in a matter of days, Sam. And once—”

A loud crashing sound drowned out the rest of his words. They jerked around to see Pete stamping and leaping madly beside the desk. Dickson shouted an order for him to stop, but the robot went on unheedingly. By the time Sam could reach him, Pete had reduced whatever had been in the opened desk drawer to a mess of plastic lumps and metal scraps that could never have meaning. Then he halted, standing quietly in the ruin he had made.

Dickson approached him, striving for a note of firm command. “I’m giving you an order, Pete. I order you to tell me what that was.”

Pete made no answer. He began backing away, shaking his head.

And more orders from Dickson only made him back away faster.

IV

“Oh, let him alone,” Gregg said at last. “It’s your damned prime law—something that Pete thinks might harm men, obviously. That means anything from the ultimate weapon to some alien dirty picture. And since he thinks telling us would also harm us, we’ll never know whether it was important or not. It’s my fault for letting a rule- and fool-crippled robot in here and not having him watched. Take him back to the digger, Dr. Dickson.”

Lee held out a thick wrist, indicating his watch. “We’d all better go back with the slavemaster, Jim. By the time we can weld some mesh over the entrance to keep trolls out, it’ll be night.”

Gregg frowned in surprise as he checked his own watch. Then he nodded. He gathered up a set of the dictionary sheets, selected a couple of books at random, and fell in beside Sam as they headed back through the tunnel. But as they neared the entrance, he stopped.

“I think this place is taboo to trolls, even without the gate. But I’ll feel better making sure. You go on, Sam.”

“You go on. I wasn’t planning on getting much sleep tonight, anyhow,” Sam told him with heavy sarcasm.

Gregg chuckled. “You’re right, of course. Thanks. I’ll send down fresh batteries and my rifle before we leave. See you in the morning.”

He hurried after the others, and Sam turned back, studying the situation. From the desk, he could see a good distance up the tunnel by arranging the light carefully. And by turning in the seat, he could reach most of the books. He spread out the second word list and prepared to do some serious studying.

Barney brought the rifle and batteries down a quarter hour later. He pulled a sandwich out of his pouch and sat down on the ruined fuel cell to eat it. “They got the gate welded down pretty good,” he announced casually.

Sam shook his head gently in the gesture he used where a man would smile. “Thanks, Barney.”

“Don’t mention it, youngster. Temperature ought to stay comfortable down here, at least.” The man finished eating and drew a thin air mattress from his pouch. When it had blown itself up, he began kicking an area free of debris. “Wake me if anything should happen.”

Somehow, in spite of the oxygen mask, Barney managed to snore. But Sam was rather glad of the sound. He stared down at the old man fondly, remembering the first human he’d ever loved. Pop had been officially only head janitor of the robot school, but he’d somehow managed to provide an endless stream of games and stories for the students. He’d laughed away their failures and given them all the same advice when they finally graduated. By now, he was a legend among robots, and his words were hallowed in tradition.

Pete had missed all that in his conditioning. It was no wonder he acted more like a half-trained dog than a real person.

* * * *

At midnight, Sam checked the tunnel. The gate was still secure. It was too dark to spot the trolls, but he could hear them yammering all around, with one repeated cry: Yar Noo biliyet! The first two words meant “Rock Devil” and the third was obscene. They were working up to something, but they didn’t sound dangerous yet.

He went back to pore over the books. He’d given up any hope of making sense by translation; too many words were missing from the bilingual sheets for immediate sense. He was looking for the few books that had pictures, studying those. One showed a night sky with a star pattern that might help astronomers locate the alien sun. Another yielded several group scenes, and those disturbed him. They showed a dark, graceful people with two legs and four slender arms. But their skins were too smooth, their bodies too similar, and their heads too identically spherical.

“Something eating you, Sam?” Barney asked suddenly. He must have been awake for some time, since he was already chewing away at a cud of tobacco.

Sam shook his head, unwilling to state his suspicions yet.

Barney grunted. “Well, something’s eating me. From where I sit, I can see half an inch showing under the bottom plate of your desk, and I want to know what’s underneath, holding it up. Think you can move it?”

A minute later, they were looking at the spot where the desk had stood. A smooth, oval hole had been cut through the metal floor and dug into the ground below. Heavy rocks were jammed tightly together to fill it completely.

Barney looked at the rocks and then at the desk that had been placed over them. “Looks like something was meant to stay down there. I got a hunch we’re going to have a lot of work getting it out.”

It wasn’t too hard at first, though some of the stones weighed more than a hundred pounds. But the work increased with depth, and they were eight feet down before they reached the last layer. The men and Pete had already returned in the morning and were clustered around the hole when Sam finally freed what lay at the bottom and passed it up.

The head was no longer spherical, the metal chest was horribly crushed, and most of the brown enamel was gone. But as Barney and Lee stretched it out on the floor, it was still slim and graceful, with two legs and four slender arms, like all the people in the book.

And like them…it was a robot.

“So that’s the Rock Devil,” Gregg said finally, without surprise.

Dickson was studying it with horrified fascination. “It doesn’t look much like rock to me.”

“It does to trolls,” Sam told him. “If a thing bleeds or gives sap, it’s bel—food; otherwise, it’s yar—rock. Yar that acts like bel is a devil—noo—and smart trolls ordinarily look the other way. But this is the ultimate Yar Noo and supposed to drive them into a killing rage.”

“It’s going to complicate our problem, but I guess it’s worth the risk,” Gregg decided. “Any trouble here last night?”

“No troll trouble. Just a lot of noise.”

Gregg frowned. “That’s odd. We had a sort of war dance around us all night. Two of the chiefs I know came to warn me that if we didn’t make sure the Rock Devil was dead and get out quickly they couldn’t control things much longer. I’ve abandoned camp already. I figured on loading up here and heading south to Ramses at once. But now we’ve got to smuggle the Rock Devil out. Any idea how?”

“Cover him with a piece of canvas, and I’ll carry him down and load him in the digger,” Sam suggested. It was the simplest way.

* * * *

Apparently it was too simple for the others. Eventually they decided to make four drawstring bags from the canvas. One would contain the Rock Devil, and three others would be filled to the same size with everything else. These would be lowered one at a time by crane.

The bag with the Rock Devil would go last, after they saw the troll reaction to the others.

“Pete will have to operate the crane,” Gregg decided. “Dickson, you supervise and make sure there are no slip-ups this time. Lee and Barney can improvise the bags, then go down to stow things in the digger. Sam, you’ll stay with me and select what we’ll take.”

The thick canvas bags were clumsy, but they seemed strong enough. Sam bundled the alien into the first to give them a model for the size of the others. Then they began stripping the dome of all of any value. Two books, the writing machine, and Sam’s spare batteries were left to be carried out after the bags were safely down. Sam slung the rifle over his shoulder and began moving the sacks to the entrance.

The trolls were about a hundred feet beyond the digger and herded between all the mounds. They kept their fixed stares on the ledge as Sam moved out with a sack, jabbering obscenities, but made no sign of taking other action.

At least Pete could handle simple machine controls well enough. The shovel swung up smoothly to level with the ledge, accepted the first sack from Sam, and carried it down directly to where Lee and Barney were waiting. The trolls hopped about and yelled, but they made no effort to interfere. The second and third sacks followed. Sam waited until all were stowed in the digger before bringing out the one with the alien and dropping it onto the shovel.

The crane drew backwards—and swung suddenly away from the men waiting below! The digger tracks spun into motion, slewing the machine around to face away from tin-mound. Inside it, Sam could see Dickson pounding futilely against Pete’s hands. Then the man gave up and ran back to leap for the machine and stumble toward Lee and Barney. Gregg started toward the ledge, but Sam pulled him back.

“We’re better off up here, Jim, if there’s trouble. Call the others up.”

Gregg yelled down, and all three men began climbing toward the ledge. Dickson looked sick as Sam pulled him up the last few feet.

The digger was rolling forward now. Trolls spilled back and aside as it headed for them. The machine drove on for perhaps two hundred feet along the old road toward camp until it came to a rocky section. Then the shovel opened and spilled its contents directly in front of one caterpillar tread. The churning plates of the track hit the sack and began pounding across it, carrying ten tons of weight to grind it against the rock. The digger reversed itself and reversed again. It made six more passes before it stopped and Pete dropped from it. The robot began walking back toward the mound casually. Trolls jittered and then made room for him.

“They didn’t spot it,” Gregg said suddenly. “They don’t know we had the Rock Devil. Sam, if we can get the digger back, we may still get out of this.”

Sam nodded and threw his amperage drain to emergency maximum, prepared to drop and run for it. Then he stopped as his heightened hearing brought him the sound of Pete’s voice.

The words were in Old Trollish, but the PT brain of the robot had learned the lesson well—and somehow he had managed to guess the cant of primitive oratory. “Yar Noo alidet! The Rock Devil is dead! We bound him and cast him from us, we ground him into the dust of the earth, we made him like the grains of sand that blow before the wind. His breath is spent, and his power, forgotten. He cannot rise again!”

There was a delay as the ancient form of the language filtered through to the trolls. Then they were leaping for the area where the digger had destroyed the alien. And a moment later, the message was being relayed forward.

“Yar Noo alidet! Yar Noo alidet!”

V

The results came quickly. There was a series of wild cries, and then the trolls were leaping forward toward the mound, drawing their weapons. Bows were lifted, and arrows began whistling through the air. They fell short, but the next flight would reach.

Sam swung his arms, shoving the men down the tunnel. He turned again, yanked the rifle from his back, and sighted quickly. He knew some of the chiefs, and he picked them off while the arrows banged against him. At the death of the fifth chief, the trolls faltered. As the eighth dropped, they began retreating.

He lowered the rifle and stretched out a hand to help Pete up, while Gregg came from the tunnel entrance to join them, then stood watching as the last of the trolls vanished behind the digger and nearby mounds. Now that the first rush had failed, they would spend the day picking new chiefs and yelling their courage back, waiting for the obvious advantage of darkness. But meantime, they were making sure that their victims had no safe line of escape.

“They may relax a little near sundown,” Sam decided. “Then if I can reach the digger while you cover me with the rifle, we may have a chance. I’ll back it up to the mound, and you’ll have to make a concerted run for it. If you get inside, it may protect us long enough to get through the mob and outrun them.” Back inside the little dome, the men listened grimly as Gregg outlined the situation and plan to them. Lee and Barney nodded as he finished.

Dickson shook his head. “Not all of us. Dr. Gregg, that robot isn’t safe with us. He deliberately refused to obey. He got us into this!”

“Sit down, Dr. Frankenstein,” Lee said sharply. A big hand put force behind his order. “We’re all in this together—even you! With what I heard about the danger to us of the Rock Devil and the trolls’ insistence we kill it, I thought Pete was doing the right thing. And I still don’t blame him. What got into the trolls, anyhow, Jim?”

Gregg shrugged. “Who knows? We can guess. But Sam and I were always uncertain about the legends and the parts we couldn’t seem to get. We knew they were afraid of his reviving—but now it seems the only reason they didn’t attack us before was because of that fear. They liked his trinkets, but when he wanted to change their ways, they killed and buried him. That’s all we know.”

“No, Jim,” Sam corrected him. “They didn’t bury him. That hole in the floor isn’t troll work. There had to be at least two aliens. One found the first and buried him, then took such vengeance on the trolls that they still remember. They must have thought it was the same one. So they are afraid he’ll revive again.”

“You mean that robot’s master was with him?” Dickson asked.

* * * *

Gregg shook his head. “There were no alien ‘masters.’ From the books I studied, the masters died off so long ago that the robot branch no longer has clear records of it. Something happened—perhaps some disease—and the robots carried on alone.”

“Disease? Murder!” Dickson came to his feet with a scream, his face taut and white with all the ancient Earth fears he had bottled up under his mask of scientific study. “The robots killed their masters. Just as ours will do. We’re not safe while a single robot exists. They’re the most dangerous threat to our lives—and you sit there!”

Lee was moving toward him, but Gregg’s fist stopped the tirade. “Pete, don’t listen—”

But Gregg’s words were too late. Pete swung abruptly, grabbing Sam’s spare batteries from the desk, and he was pounding up the tunnel. By the time Sam could get past the tangle of men around Dickson, the other robot had vanished.

“He’ll kill himself,” Gregg shouted. “He has to. If he’s the greatest source of harm to men, that damned first law has to negate the third. We’ve got to stop him.”

Sam shook his head, but he followed the others up the tunnel to the entrance. Even Dickson managed to stagger along with the others, moaning and grimacing with the pain of his jaw as sanity returned to him.

At first, there was no sign of Pete. Then they saw that the trolls had begun to stream forth and cluster below the ledge, their vulpine stares fixed upwards. Sam followed their gaze and finally spotted the other robot. Pete had almost reached the top of the mound, scrambling and fighting for holds in the crumbling surface. As they looked, he reached the peak and sat down upon it.

Methodically, he began to open his chest plate and change from his fresh batteries to the used spares he had scooped from the desk. Below, the trolls began screaming. “Yar! Yar Noo!”

“Yar Noo haremet!” Pete shouted back in old Trollish. “The Rock Devil has returned! You did evil as you did of old, and the Rock Devil came from the dust and entered into this body and became strong again. Fear me and run from me, little bugs of evil!”

Most of them had already begun to draw back, though a few were lifting their bows. Now Pete stood up again, the two fresh batteries in his hands.

And Sam could see that the protective caps were removed, exposing the bare terminals.

“Down!” he cried sharply to the men.

Pete jumped, holding the batteries, moving them precisely and slowly toward his own metal body. And just before he landed among the screaming trolls, he moved his hands to short the terminals against himself.

Those batteries were capable of holding a hundred ampere hours at more than a hundred volts pressure as a strain in the space within them. And now suddenly twenty kilowatt hours of potential energy screamed out in a terrible attempt to become raw heat.

When the explosion of light and heat was over, there were no trolls except the dead and the fleeing.

Pete’s torment was over. The laws and idiocy that had made his life a hell where all he did was wrong had been repealed.

* * * *

“We can go home now,” Sam told the men as they emerged from the tunnel. “I guess we can even go out to the stars on the great Gregg Expedition to find the aliens. But first, Barney, will you help me take what’s left of Pete and bury him in the hole like the other Rock Devil?”

And with the mangled body would go a card that Sam had carried for all the years since he had graduated—a cheap little printed card of congratulations with the scrawl of a janitor on the back. It was the code a man had inscribed for Sam:

Take care of yourself—and always try to leave things a little better for the next fellow.

Pete hadn’t been given such a code, of course. But he’d earned the right to it, nonetheless.