the city before he found the man. He would have to work quickly.
He found the first of the murdered New Law robots just a few hundred meters from the airlocks. The body was sprawled face down on the floor of the corridor, shot through the back of the head in much the same way as the victims at the aircar site. Caliban knelt down next to the body and turned it over. It was Lancon-03, Prospero’s most recent protege. Lancon, it would seem, had gotten in somebody’s way.
But there was nothing Caliban could do for Lancon now—and time was short. He had to keep moving. He spotted three more murdered New Laws as he walked along. There had been nothing but a few caretakers left behind in the city to deal with last-minute details. It would seem that the kidnappers had dealt with all of them.
Each should have been mourned over, praised, remembered—but time was short. Caliban broke into a trot, hurrying forward through the sterile emptiness of the depopulated robot city. Every tidy, immaculate, sensible, utilitarian, carefully laid-out passage and street and building now was meaningless, useless. The empty town of Depot had seemed like a place that was dying, lost, abandoned. Somehow, the empty town of Valhalla seemed like a place that had never lived in the first place. Caliban thrust such thoughts from his mind and hurried on up the ramps to the upper level, the huge half-cylinder-on-its-side that was the main gallery of Valhalla. He jogged up the central boulevard and into the main administration building of the city. He slowed, and moved more cautiously up the broad, sloping ramp that led to the building’s upper story and the executive offices there.
And suddenly Caliban heard a voice. A human voice. Beddle’s voice. He tried to make out the words as he got closer. At first, he could only understand a word here and there. “—ever you want to know… promise you that —” He moved in closer, until he was right outside the door, and then he could hear it all. “I will make any promises you like, and put them in writing,” Beddle said. “Just let me out of here. You have convinced me that your cause is just. Let me leave, and—”
“If I let you leave, you will prove yourself a liar,” another voice said.
Prospero’s voice.
Caliban felt a fresh wave of revulsion wash over him. He had known it. He had been sure of it. But knowledge and proof were two different things. Up until that moment, some small part of him had prayed that he was wrong. But now that hope was gone.
He stepped into the office—Prospero’s office, his blaster at the ready. “Liar or no,” Caliban said, “you will let this human go.”
A surreal tableau greeted Caliban as he came into the room, a whole series of complex details that he took in all at once, in the space of less than a second. Prospero stood on one side of the room, in front of his desk, a magnificent panorama of the lower city visible through the view window behind him. A system of wall-mounted photosensors divided the room in two lengthwise. The sensors were attached to one long wall of the room, and spaced about twenty centimeters apart in a vertical line that went from ceiling to floor. Beam emitters lined the opposite wall, their beams aimed squarely at the photosensors, and bright enough to be plainly visible.
A complicated-looking device, roughly torpedo-shaped, but with a powerful-looking drillhead mounted on its nose, lay on the ground at Prospero’s feet. A cable led from an open hatch on the device to a junction box on the floor. Another cable led from the junction box to the photosensors.
On the opposite side of the room, behind the optical barrier formed by the photosensors, stood Simcor Beddle, leader of the Ironheads. He looked haggard and gaunt, his eyes wild with fear. He was so terrified he hardly seemed to know that anyone new had come into the room.
Beddle was a sorry sight. He was unshaven, and his hair was badly mussed. He wore a sort of shapeless gray jumpsuit that did not seem to hang on him properly, as if he had had trouble doing up the fasteners. There were sweat stains under his armpits, and a greasy sheen of sweat on his face. Simcor Beddle. Every bit of the power, the authority, the arrogance attached to his name had been swept away. He seemed numbed, in shock, scarcely aware of his surroundings. He looked toward Caliban, and yet seemed to look right through him. “Who’s there?” he demanded. “Who’s there at the door?”
Caliban ignored him, and continued his survey of the room. There was a portable refresher unit in Beddle’s side of the room, and a large supply of bottled water and survival rations stacked up on the opposite side of the room from the refresher. A primitive cot, with one blanket and one pillow, stood in the center of the cell.
And Caliban understood. The torpedo-shaped device was, of course, the burrow bomb. It was hooked up to the photosensors. If Beddle tried to step across the sensor barrier, the bomb would go up—or at least Prospero had convinced him that it would. It came to much the same thing.
But Caliban understood more than that. A robot may not injure a human being. That was the New First Law, in its entirety. And, at least by the most parsimonious and niggardly of interpretations, Prospero had not in literal fact harmed Beddle. No doubt he had carried some utterly safe anesthetic with him when he had hidden himself aboard Beddle’s aircar. He had seen to it that the unconscious Beddle had plenty of air for his ride across the lakebed in the cargo roller. And he had provided Beddle with ample food and water, adequate sanitation facilities, serviceable clothes, and a decent bed. He had done the man no harm at all, at least in any literal, physical sense.
And if Beddle elected to stay where he was, he would not come to any harm at Prospero’s hand. And if he crossed the optical sensor barrier, it would be Beddle’s action—not Prospero’s—that would set off the bomb and destroy him. Beddle would kill himself with the bomb he had meant to use to kill a city full of New Law robots.
And Prospero would not be forced to interfere. The second clause of the original First Law required a robot to take action to prevent harm. A Three-Law robot could not stand idly by if Beddle endangered himself. But not so the New Law robots. Prospero could, through inaction, allow a human to come to harm.
And when the comet struck then Beddle would die, yes, but not through any action of Prospero’s. It would be the actions of others-of Davlo Lentrall, of Alvar Kresh, of all the engineers and designers and pilots who moved the comet—that killed him. It would not be Prospero.
Prospero had found a loophole in the New First Law. He had found a way to kill without killing. All it required was as miserly—and as vicious—a parsing of the New First Law as Caliban could imagine.
And it also required Prospero to be half mad, at least. The leader of the New Law robots turned to face Caliban, and it was instantly obvious that Prospero could meet that requirement without the slightest difficulty. His orange eyes glowed with too brilliant a fire. The fingers of his left hand were twitching spasmodically. Dealing with his parsimonious interpretation New First Law had clearly imposed a tremendous amount of stress. And clearly, Prospero had cracked under the pressure. “Caliban!” he cried out, a wild pleasure in his voice. “I knew it would be you. I knew if anyone figured it out, it would be you.”
“Prospero, you are insane,” Caliban said. “Stop this. Stop this now, and let us all depart.”
“How did you figure it out?” Prospero asked, completely ignoring what Caliban had said. He turned more fully toward Caliban, moving a bit too quickly, and nearly overbalanced himself. “What was the clue that led you here?”
“Norlan Fiyle said that whoever killed the robots at the aircar hated Three Law robots. You have always held them in contempt.”
“Willing slaves,” Prospero said. “Collaborators in their own oppression. They don’t matter.”
“And what of Lancon-03 and the other New Law robots that lie dead in the halls of Valhalla?”
“Unfortunate, but necessary. They would have interfered. They would have stopped me. I had to choose the greatest good for the greatest number. Now they cannot stop me.” Prospero’s gaze shifted to the desk behind him. There was a blaster on it.
Caliban ignored the implied threat. “I can stop you,” he said. “I will.”
“No,” said Prospero. “No, you can’t. You won’t.”
“I have no choice,” said Caliban. “If I can deduce the truth, so will others. The moment the humans realize that a New Law robot engineered the death of a human being, the New Law robots will be exterminated.”
“I have not engineered his death!” Prospero protested in a voice that suddenly turned shrill. “I have not harmed a human being. I… I merely offered choices to others.”
“Choices that were bad or impossible for everyone else, and good only for you. If they paid the ransom money, it would be traced and Gildern and the Ironheads would be discredited. If they diverted the comet, the city of Valhalla would be saved-at the expense of the planet’s future. If they refused to do either, than Simcor Beddle, the greatest enemy of the New Law robots, the man who wanted you destroyed, would die, and the Ironheads be badly weakened. That was the other part of the puzzle for me. You were the only suspect who stood to gain no
