about to be destroyed?"
"I do not apologize for rushing the evacuation of Valhalla," Prospero said. "Transport craft became available, and I deemed it wise to use them when we could, for fear they would not be there when we needed them. A schedule change in our favor reminded me that one to our disadvantage could happen just as easily."
"Your point is taken," said Caliban.
"As for the need to keep the city hidden even now, we might well need to use the same concealment technique again in future. Further, one must consider the human viewpoint. We might gain some psychological advantage in future from the story of the city they never found. We might even be able to foster some legend that the city still existed, that everyone was looking in completely the wrong place. That could be useful, one day. Besides, there are things about us that could be learned by examining Valhalla. We have enough weaknesses and vulnerabilities already. We do not need to offer the humans more advantages over us."
Caliban considered for a moment. Once again, he was impressed by the amount of thought Prospero had put into things. "Your arguments are well formed, friend Prospero. You are quite right. We must do all we can do. Now I will let you get on with your work."
"Thank you for informing me of this new development, friend Caliban. I must thank Dr. Leving too, of course-once it is safe to do so. Of all humans, she at least is a woman who keeps faith."
"Agreed. She is an admirable woman," said Caliban. "Goodbye for now, friend Prospero."
"But not goodbye for long, I am sure," said Prospero, his attention already on the next item requiring his attention.
Caliban reopened the door and left Prospero's office. He made his way downstairs, and out into the busy, bustling street. He looked up into the sky, to the fat, bright point of light that grew larger with every passing moment. Closer. Closer. All the time closer. There was so little time left.
What was it Prospero had said? We must do all the things we can to protect the New Law robots. In recent days Caliban had felt himself drawn back to their cause. The more the world had no time for them, no interest in them, the more it seemed ready to let them all die if that was marginally more convenient, the more he empathized with them. AU the things we can. It would require breaking his word to Fredda Leving. It would require doing her a small amount of harm-but surely nothing she could not recover from. And it could prevent a brutal purge of New Law robots. Being a No Law robot-the only No Law robot-should have meant Caliban could act without compulsion. But there were more things than hard-wired, preprogrammed Laws that could compel a being to act.
Caliban turned and headed down the street, in the direction of the temporary field headquarters of the Combined Infernal Police, in Constable Bukket's old offices.
DONALD 111 WAITED. HIDING in the woods a kilometer or two from the Winter Residence. A cleft in an outcropping of rock provided shielding not only from visual detection, but from infrared and most other sorts of detectors. So long as he operated at minimum power, thus cutting back on waste heat and other detectable emissions, he judged that he ought to be able to stay hidden long enough-though how long that would be was impossible to say.
He had deliberately violated his master's very specific order. First Law had forced him to do so. Had he obeyed, the governor would no doubt have powered him down to prevent him telling what he knew to other Three-Law robots. Allowing that to happen would have been inaction that allowed harm to a human being. He could not act to save Beddle if he were powered down.
But he had not yet taken any action to save Beddle. As yet it was not necessary. Even if Beddle were in the comet impact area, and there was no particular reason to assume that he was, there were still just over three days left in which the humans could do their best to save him. Donald understood perfectly well that any action to save Beddle might well cause harm to other humans, for example by compelling robot aircar pilots to refuse to transport vital equipment while they joined the search. The more robots there were in the impact area this close to the comet's arrival, the