“Did not disobey! Was not present when order given. Sent-I was sent-on an errand. I came back after.”

“Then how do you know the order was given?”

“Because it was given before! Other times!”

Other times?Donald was more and more amazed. “Who gave it? What other times? Who gave the order? Why did that person give the order?”

Daabor 5132’s head jerked abruptly to one side. “Cannot say. Ordered not to tell. Ordered we were ordered not to say we were sent away, either-but now going away caused harm to human harm harm harm-”

And with a low strangling noise, Daabor 5132 froze up. Its green eyes flared bright for a moment and then went dark.

Donald stared sadly at what had been a reasoning being brief moments before. There could be no question that he had chosen rightly. Daabor 5132 would have failed within a few minutes in any event.

At least there was the hope that a skilled human roboticist could get further information out of the other staff robots.

Donald turned away from the ruined maintenance robot and turned his attention back toward the human victim on the floor, surrounded by the med-robots.

It was the sight that had destroyed the Daabor robot, but Donald knew he was, quite literally, made of sterner stuff. Fredda Leving herself had adjusted his First, Second, and Third Law potential with the express purpose of making him capable of performing police work.

Donald 111 stared at the scene before him, feeling the sort of First Law tension familiar to a sheriff’s robot: Here was a human being in pain, in danger, and yet he could not act. The med-robots were here for that, and they could aid Fredda Leving far more competently than he ever could. Donald knew that, and restrained himself, but the First Law was quite clear and emphatic:A robot may not injure a human being, or, through inaction, allow a human being to come to harm. No loopholes, no exceptions.

But to aidthis human would be to interfere with the work of the med-robots, thus at least potentially bringingharm to Fredda Leving. Therefore, to do nothing was to aid her. But he was enjoined against doing nothing, and yet to aid her would be to interfere-Donald fought down the tremors inside his mind as his positronic brain dealt with the same dissonance that had destroyed Daabor 5132. Donald knew that his police-robot adjustments would see to it he survived the episode, as he had so many in the past, but that did not make it any less unpleasant.

Humans, on the other hand: These days, the sight of blood and violence scarcely bothered Alvar Kresh. Human beings could get used to such things. They could adapt. Donald knew that was so intellectually, he had observed it, but he could not understand how it was possible. To see a human in distress, in danger, to see a human as the victim of violence, even dead, and to be unmoved-that was simply beyond his comprehension.

But human or robot, the police saw a lot, especially on Inferno, and experience did make it easier in some ways. The paths of his positronic brain were well worn with the knowledge of how to deal with this situation, however disturbing that might be. Stay back. Observe. Gather data. Let the meds do their work.

And then wait for the human, wait for Alvar Kresh, wait for the Sheriff of the city of Hades.

The med-robots worked on the still form, rushing to stabilize her, ensure her blood supply, patching up the gashes in her shoulder and face, attaching monitor pads and drug infusers, moving her to a lift stretcher, shrouding her in blankets, inserting a breather tube into her mouth, cocooning her from sight behind their protections and ministrations.And that is how it should be, Donald thought.Robots are the shield between humans and the dangers of the world.

Though the shield had clearly failed this time. It was a miracle that Fredda Leving was even alive. By all appearances the attack had been remarkably violent. But who had done this, and why?

The observer robots hovered about, recording the images of this scene from every angle. Maybe their data would be of some use. Let them soak in all the details. Donald shifted his attention to the two sets of bloody footprints that led from the body. He had already tracked them out as far as they went. Both sets of prints faded away into invisibility after only a hundred meters or so, and he let it go at that. Police technical robots were already using molecular sniffers to try to extend the trails, but they wouldn’t get anywhere. They never did.

But there was no missing the key fact, the vital piece of evidence. And no denying the horrible, unthinkable conclusion they suggested.

Both sets of footprints were robotic.Both sets. Donald, designed, programmed, trained in police work, could not avoid making the obvious and terrifying inference.

But it could not be. It couldn’t be.

Donald devoutly wished for Alvar Kresh to arrive. Let a human take over, let someone who could get used to such things deal with the impossible thought that a robot could have struck Fredda Leving from behind.

THE night sky roared past Sheriff Alvar Kresh, and the scattered lights of buildings in Hades’s outskirts gleamed bright below. He looked up into the dark sky and saw the bright stars glowing down at him. A beautiful night, a perfect night for a speed run over the city, something he only got the chance to do on official business, and he had to be in a foul mood.

He did not care for being awakened in the middle of the night, did not care for anyone but Donald helping him to dress.

He tried to cheer himself up, to soothe himself. He looked out into the night. Tonight was the best weather Hades had had in a long time. No sandstorms, no dust-haze. There was even a fresh tang of seawater blowing in off the Great Bay.

At least he could burn off his adrenaline and his anger by flying his aircar himself, rather than leaving the chore to a robot. He took a certain pride in that. Few humans even knew how to fly an aircar. Most people felt the chore of controlling an aircraft beneath them. They let the robots do it. No doubt most people thought it was damned odd that Alvar liked to fly his own car. But few people were likely to say that to the Sheriff’s face.

Alvar Kresh yawned and blinked, and punched the coffee button on the aircar’s beverage dispenser. He was alert, clear-eyed, but there was still a shroud of tiredness over him, and the first sip of the coffee was welcome. The aircar sped on through the night as he flew it one-handed, drinking his coffee. He grinned.Lucky Donald isn’t here, he thought. It was stunts like flying one-handed that made it all but impossible for him to fly his own car when Donald, or indeed any robot, was on board. One false move and the robot would instantly leap into the copilot’s seat and take over the craft’s controls.

Ah, well. Maybe the Settlers sneered at robots, but no Spacer world could function for thirty seconds without them. That having been said, the damned things could be incredibly infuriating all the same.

Alvar Kresh forced himself to calmness. He had been roused from a sound sleep in the dead of night, and he knew from bitter experience that interrupted sleep made him more edgy than usual. He had learned long ago that he needed to do something to take the edge off himself when he was too keyed up, or else he was likely to take someone’ s head off instead.

Alvar breathed the cool thin air. A nightflight over the desert at speed with the top open and the wind howling through his thick thatch of white hair helped drain away some of his temper, his tension.

But crimes of violence were still rare enough in Hades for him to take them personally, to get angry and stay that way. He needed that anger. This savage and cowardly attack on a leading scientist was intolerable. Maybe he did not agree with Fredda Leving’s politics, but he knew better than most that neither the Spacer worlds in general nor Inferno in particular could afford the loss of any talented individual.