FREDDA LEVING POINTED her finger at another party guest and watched him disappear. It was a strange sort of game, but one that needed playing. She rubbed her eyes and sighed.

"That's as many as I can get in this pass. Run it back again, Donald," she said. "Let's try that sequence again."

The integrator's three-dimensional images scrolled back to the beginning again and started over. Fredda sat and watched as the party guests started to filter into the Residence. By now well over half of the people at the party were missing. Every time Fredda or Donald or the computer managed to identify a person, they would eliminate his or her image trail from the integrator's event sequence for the evening.

The imagery integrator was a Settler machine that was a close cousin to the simglobe, designed to take in all manner of visual images and combine then into a single three-dimensional whole. Four dimensions, if you counted time.

And the more people that were missing from its images, the better. They needed to know if there had been anyone who did not belong at the reception, and what better way to do that than by eliminating those who did?

It was a shame that the Settlers' access recorder system wasn't useful in these circumstances. It could automatically record comings and goings of each person, and identify each against its access authority list-but such systems were designed to work in more orderly settings than a massive reception. Even the sophisticated access recorder in use at the Residence had been overwhelmed by the crush of bodies at the reception. Too many people, too many strangers, too many people coming in too quickly.

They had fed the integrator everything-the architectural plans of the Residence, all the news video and 3-D imagery taken the night of the assassination, detailed 2-D and 3-D still images of the Residence's interior and exterior, still pictures of all the guests, and whatever other information Donald had been able to get together.

The integrating simulator had swallowed it all up, and used the masses of data to produce the computer model that Fredda and Donald had been watching for entirely too long. The integrator could present any view of the interior or exterior of the Residence, at any scale, as seen from any point in time in thirty-two hours, the time period under investigation. It could run its imagery forward or backwards at any speed, or freeze it at any point.

It could fill in the blanks from one image by lifting them from another. If, for example, it saw a given man was wearing blue pants and red shoes in a full view from the front, but noted he had a bald spot in a view from the rear where his legs were obscured, it would add both data points to the full image bank of the individual. Given enough information, the integrator could present the man at any time, from any angle-or subtract him from the scene and let you see the woman behind him who had been hidden from the cameras in real life, producing a view of her built up from her image bank. The integrator could not, of course, show what she had been doing while hidden from view, but it could at least show where she had been.

Indeed, much of what the integrator showed was conjectural. Not every part of the reception had been recorded. There had been any number of times and places where there were no camera images, where a certain amount of guesswork was required of the operator. That led to guessing, of course. And guessing made you wonder. What was everyone up to when they were out of view?

And that was the question that made it all turn paranoid. Subject X was seen leaving room A and then appeared forty seconds later appearing in room B, with no video imagery of what went on in the hallway between. Had X moved in the straight-line direction, as seemed reasonable, or had X done something nefarious the moment he or she was out of camera view? Was forty seconds an unwarranted delay, or was it about as long as the trip should have taken? Was the delay caused by some fiendish part of the plot, or by a call of nature, or just a moment's pause away from the crush of the crowd?

And was it paranoid to ask such questions? After all, someone in that swirl of visitors had killed Chanto Grieg. Several someones had been involved. Somewhere in the evening, someone had to have done something that he or she would not wish to be observed, and presumably had had the sense to do it out of sight of the cameras. Somewhere in all the delays explained by innocent stops in the refresher, and chance meetings in the hallways, the acts leading up to murder were being hidden.

But where? Where in all the background clutter of people at a party were the guilty acts? The best way to find out seemed to be eliminating all the innocent acts and examining what was left.

So here they were, erasing the innocent from the image trail, in hopes of leaving none but the guilty behind.

It was a tricky job, for the integrator images were not infallible, or even completely realistic. If there were imagery, say, from a camera in a hallway that showed a man entering a room that had no camera, the integrator had no way of knowing what the man did once he was out of camera range. Absent instruction from the operator, the simulacrum of the man in the room would just stand there, in the center of the room, a motionless wooden doll, until such time as the hall cameras picked him up reentering the hall. Then the simulacrum would move, stiff-leggedly, toward the door, melding into real-life imagery as the man came back into camera view.

Even stranger were the half people that flickered into existence here and there-half-seen arms or legs or torsos that the integrator was unable to link to any specific person. It did not exclude them until told to do so.

Half of the images Fredda was seeing were at least in part imaginary. The integrator didn't care. Given the appropriate data, it was quite happy to present hypothetical-or quite spurious-imagery. It could be instructed to run various versions of events, running through all the possibilities of who went where during the moments they were not actually in view of a camera. Even the hypothetical images were useful in sorting out the possibilities.

By now, with more than half the guests accounted for-and thus eliminated-the images were getting more and more surreal. People were talking to other people who weren't there anymore. What had been tight clumps of people were now isolated twos and threes.

Computers and robots should have been able to do this job, but no robot or computer had ever been good enough at pattern recognition, at being able to see the whole when looking at only a part. Even their thousands of years of development were no match for the billions of years of human evolution. That was why Fredda had drawn this duty along with Donald. She could see the bit of chin, or the fleeting, partially obscured profile, and say it was the same face she had seen twenty minutes before, allowing the integrator to connect two image sequences as one person. Better still, Fredda knew lots of people' and was able to identify any number of blurry faces the integrator was not able to match up with its still image identity file.

It was strange to see it all this way, from this godlike angle, but it was a remarkably useful way to sort out the movements of this person and that. Stranger still to see her own image and eliminate it, to see Alvar Kresh and make him vanish. It made her doubt his reality-and her own.

But should she make Alvar vanish? After all, he was the one who found the body. That in and of itself was a trifle suspicious. Donald had been a few steps behind him at the time. Kresh had not been alone in Grieg's room for long, but suppose it had been for long enough-and even though it was a point open to interpretation, you could read the fact that Grieg had offered no struggle as a hint that he had been killed by someone he knew...

It seemed absurd-and yet someone had killed Grieg, and as of right now the rest of the universe only had Kresh's word for it that he had found Grieg dead.

No. It couldn't be. Not Kresh. The man might be stubborn and infuriating as hell, but there was no more honorable man on the planet. It was absurd to think that a man of his character could have done it. She knew him too well to believe such things. She was reluctant to admit such a thing, even to herself, but she liked him too well to believe such a thing.

Fredda glanced at Donald, seated impassively at the integrator's control panel. Did fretful, disturbing thoughts like that flit through his mind? Was he troubled by such delusional nonsense? She, Fredda, ought to know. She had, after all, designed his brain, his mind, herself. But that meant nothing at a time like this. The short, sky-blue robot seemed unflappable-but what lurked under the surface? Was he intelligent enough to have doubts, to see that the universe was not the well-ordered, every-peg-in-its-proper-hole place that the Three Laws would make it seem? He was a police robot, after all, and knew as well as any robot in existence what sort of madness humans were capable of.

"Who do you think did it, Donald?" she asked, more or less on impulse. "Who killed Chanto Grieg?"

Donald had been watching the image playback, but now he turned toward Fredda and regarded her with an unreadable stare for a full ten seconds before he replied. "It is impossible for me to say," he replied. "There is so much information already in our hands, and yet so little of it appears to be useful data. We are forced to eliminate meaningless information as a first step toward the truth. "

"But you are more familiar with the case data than anyone. I know you suspect Caliban and Prospero, but leave them to one side for a moment. Who is your prime human suspect?"

Donald swiveled his head back and forth in an imitation of the human gesture of shaking his head to report uncertainty., 'I am afraid I do not, and cannot, have an opinion on that. Before I could get to who, I would have to deal with why, to the question of motive. And I am simply incapable of imagining anyone wishing the-the death of a human being. I have seen death, I have witnessed the evidence of murder. I know there must, therefore, be motives for murder. But even though I know such things are real, I still cannot imagine them. "

"Hmmph. Strange," Fredda said. "Very strange. Humans are certainly capable of all sorts of remarkable delusions-but not that particular one. Sometimes I forget just how different robots are from humans. "

"I don't think I have ever forgotten that fact, even for a moment," Donald said. "Shall we return to the task at hand?"

"Hmmm? Yes, of course. " Fredda turned back to the integrator and watched the silent dance of the simulacra. They could have put sound in, of course, but that would do little more than add to the confusion at this point.

Wait a second. Confusion. Confusion. They were missing the point of all the confusion. "Donald. Go to the time reference five minutes before the attack on Tonya Welton-and delete Tonya Weltlon, the attackers, the SSS intervention, along with all the people we've identified so far. Let's get rid of the diversion and see if we can spot what they were trying to divert us from. "

"Yes, ma'am," Donald said, manipulating the controls. He reset the system once again, running back to the proper moment in time. The image reappeared, affording the strange sight of all the bystanders reacting to the fight that was not happening. It was like watching an audience without being able to see the play. The little clumps of people turned and pointed at nothing at all in the center of the room, scuttled backwards to avoid the brawlers who were not there.

Fredda pointed at two or three of the largest groups of bystanders. They were clearly the ones being diverted, no sense in watching them. "Get rid of those people there," she said.,, And those, and those. " People vanished wholesale. Fredda let the sequence keep going. The fight had drawn people into the room from other parts of the Residence-but she was looking for the people who weren't drawn by the noise. Fredda watched until the crowds gathered, had watched the now nonexistent action, and had begun to drift away.

"Freeze it there, Donald. Mark on those people-those, and those. And that clump over by the door. All right now. Now-backtrack to five minutes before the fight, and delete all of the people just marked from the image trail. I only want to see the ones who weren't drawn to the fight."

The 3-D image blanked for a moment, then came back up on the same scene minutes before the attack. There was no one left in the Grand Hall except Caliban and Prospero. Donald was showing his prejudices again. Both Caliban and Prospero had been in sight of one video camera or another throughout the entire evening, and beyond breaking up the fight, neither of them had done anything more suspicious than chat politely with the other guests. That, clearly, was not enough to satisfy Donald. But she let it go.

After all, there was the bare possibility that he was even right to suspect them. They had Verick's statement that the two robots were the last ones to see Grieg alive.

But never mind that now. Fredda knew all about Prospero and Caliban. She was looking for unknowns, people she could not account for. "Give me an overhead view of the ground floor," Fredda said. The image of the Grand Hall vanished, to be replaced by a cutaway view of the entire lower level, presented so Fredda was looking straight down on it from overhead. "Good," she said. "Have you got all our personnel deletions saved for recall?"

"Yes, Dr. Leving. Shall I run the deleted-persons sequence forward from the same time mark before the fight?"

"In a minute, Donald. First, I want you to run it from that time with everyone still in place. Let's see the whole picture first. "

"Yes, ma'am."

The images cleared.

The 3-D image blanked for a moment, then suddenly Fredda was looking down on an eddying throng of people, talking, walking, sitting, arriving, departing, arguing, laughing. It seemed as if the entire Residence were filled with people who desired nothing more than to be somewhere they were not. Everyone was on the move. It would be almost impossible to track anyone person in all of that. Which was, no doubt, what the conspirators were counting on.

The fight started, and Fredda found that her eye was pulled toward it. People hurried in from all directions to see what was going on, and it was almost impossible to see what anyone person was doing from moment to moment.

The two men attacked Tonya Welton; she knocked one of them down, and was about to rush the second when the two robots stepped in and pulled them apart. Kresh and Donald appeared, and Kresh waded in to sort things out. The crowd started to disperse just a little as the excitement came to an end.

"All right, Donald," Fredda said. "Stop. Reset to the previous time index and run it again, with all the personnel deletions."

Donald stopped the playback and reset the system. The vision tank dissolved in a swirl of colors and then reassembled itself to show a ghostly, empty house, with but a few faceless creatures wandering the building. They were constructs, place holders to indicate unidentified people, their faces too blurry for computer or robot or human to know who they were. No doubt most or even all of them could be identified with a bit more work, but that could wait. For now they were ghosts, ghosts in the machine, faceless beings walking through a simulated landscape. Some of them vanished or reappeared now and again as they were spotted and then lost by this or that video source. Sometimes, but not always, the integrator would connect two video sequences of the same person up with animated links.

They ambled about the house, with the casual air of people with no clear goal in mind. Of course, half their motions were computerized guesses, but Fredda had the feeling the integrator was guessing right.

But then. Then she saw it. Another figure, a small, slight shadow, a pale-skinned, youthful-looking man. Thinning hair cut a bit short, wearing rather plain clothes compared to the peacock finery that had been on display everywhere else at the Residence. There he was, hanging back, arriving two or three minutes before the fight-just a few minutes after the SSS guards had obeyed the false orders to stand down. The main entrance was unguarded, wide open. There was something nervous, tense, about him. But what the devil was he doing? It was hard to read his actions with no one around him.

"Give me the fully-populated view for a second, Donald."

Suddenly the pale man was surrounded by people, and his actions became clear. He was contriving to enter the building just as a crowd of late arrivals came in, hoping, it would seem, to mix in with the crowd. The gambit worked: He got in with the rest of the group, gaining entry just thirty seconds before the fight began.

And there. There! "Donald, freeze that. Freeze it!" She leaned in close to the image tank. "Do you see it?"

"I see the subject you appear to be interested in glancing at his watch."

"Yes, but what does that say to you?"

"That he wondered what time it was."

No imagination. That was why the universe needed people and not just robots. "But who would care what time it was when they were arriving at a party? Besides which, he's a Spacer. At least he's dressed in Spacer clothes with a Spacer haircut."

"What of that?"

"Spacers hardly ever wear watches. If a Spacer needs to know what time it is, he asks his robot."

"Are you suggesting that he is checking the time in order to synchronize his actions? That he was timing his actions so he would arrive just prior to the staged fight?"

"Yes, I am suggesting that."

Donald turned to look again at the image, then turned back toward Fredda. "It seems a great deal to read into a man glancing at his wrist," he said, a bit doubtfully.

"In general, I grant you. But not too much at all to read into this man glancing at his wrist as he sneaks into this party two minutes before a fight breaks out. That is our man. I'll bet on it. Clear everyone-everyone from the image system but him and run it forward, tracking a close-up view on him."

The crowds of people vanished, and the pale-faced man in the dowdy clothes was alone in the integrator's display, with no throngs of gaily dressed party-goers to hide behind, no diversionary fights to hide behind, all his camouflage stripped away.

Fredda watched as the slightly grainy, somewhat blurred blown-up image of the man moved inside. He made his way through the entrance, into the Grand Hall-and then directly out of it again, without so much as a glance at the invisible brawl that was going on. Now and again the image of him broke up a bit, with the intervening sequences linked by animation. The effect was much more startling in close-up, as the crude overenlarged images suddenly shifted into the oversimplified images of a generic man and then back again. Every time it happened, Fredda's stomach tightened a bit, fearful that they had come to the last real video image of him, and they were about to lose him altogether.

The image of the man went down a side passage, walking purposefully, a man who knew exactly where he was going and why. No pausing at intersections or hesitating over which turning to take. Either he had been in the building at some point in the past, or he had been briefed in detail.

"Still not sure he makes sense as our man?" Fredda asked Donald.

"His actions are remarkably purposeful for a casual visitor," Donald conceded. "He appears to be making for the service areas at the rear of the building."

The pale man came to an unmarked door, glanced behind himself, opened it, stepped through, and closed it behind him. Fredda found herself staring at a blank door that had been closed in her face.

"Damn it, Donald, follow him," Fredda demanded. She was so caught up in the chase that it was a real effort of will to remember that her quarry was long gone, that she was tracking nothing more than an integrator image.

"One moment, ma'am. " Donald worked the control panel, and then looked back up at Fredda. "I'm sorry, ma'am. That is the last of the data recorded from that location, and there were no video sources on the other side of the door. I can show you what is on the other side of the door, but there is no point in placing the man's simulacrum there. There is no information at all about any other activity in that sector until the activation of the security robots. Once they were activated and deployed, they recorded that vicinity in great detail, but those records were of course destroyed with the robots. There is no further sign of the man we have been tracking in the extant records."

"Why should that one spot get detailed recording from the security robots?"

Donald ran the integrator image forward straight through the door, revealing a downward ramp beyond it. He ran the video image down the ramp and turned the corner at the bottom.

And there were the SPRs, the Sapper security robots, turned off, inert, lined up neatly.

"Burning stars," Fredda said. "Our pale-faced friend came here. Hid out in the same room as the security robots."

"So it would appear," Donald said. "Note the line of storage closets along the rear wall. I would expect that he secreted himself in one of them. "

"Probably," Fredda said. She stared at the image, determined to think it all through. If Pale-man had come down here, then he clearly knew that the security robots were to be turned off. The image before her showed the integrator's best information as to the state of the robots as of that moment. Upstairs, at the same time, Sheriff Kresh was still sorting through the chaos after the staged attack. When Pale-man came down here he would have to know that the security robots would be deployed soon afterwards.

But he would also know that the robots had been tampered with. That they would suddenly stop working, and that the building would be wide open to him. If Pale-man kept his cool, there was nothing at all to fear from being down here. All he had to do was hide, wait until the Sappers were deactivated, then come out with his blaster and-

Hold it. His blaster. There were weapon-sniffers on all the entrances to the Residence, and around the perimeter of the property. Fredda had no trouble believing that the security net could have missed an intruder slipping into the place. That sort of mistake would be easy to make. But how could the system have missed a blaster corning in? She checked the images of Pale-man. No baggy clothes or carry bag that might conceal a gun. Besides, the weapons detectors would have picked up a gun. Nothing as small as any weapon he could have been carrying would be big enough to be shielded. No. Pale-man could not possibly have been wearing one on his way in.

And therefore-therefore his blaster had been planted for him before he got in the house. And all of a sudden Fredda had a pretty damned good idea where and how.

The underground storage room that had held the SPRs looked strangely different, strangely the same, in real life. The integrator had shown an idealized version of it, pulled up from the computerized architectural plans and a few still photos, but that was only part of the strangeness. Somehow, the room looked much smaller, rather than larger, than it had through the integrator. The real-life lights were a little dimmer, and the real walls were scuffed and marked here and there in ways the sim's walls were not. The air was cool and a bit dank. Amazing the way reality could show up all the flaws of a simulation, flaws you had not even noticed in the sim.

But the key difference, of course, was that there were no neat rows of robots down here anymore. There was only one, a blown-out wreck, much more shot to hell than any of the SPRs on the upper floors had been. There was more to it than the damage being more severe. The blast holes looked different as well. But why? Why blast this one all to hell, differently and more violently than any of the others?

Fredda thought she knew the answer, the answers to those puzzles. But she could not be sure. Not yet. Not until she got a look at the fiftieth SPR. The fiftieth.

What bothered Fredda was the fact that she had not even noticed that an SPR was missing. There had been fifty SPRs to start with, but she had not even thought to do a count on them, until now. Now she knew there had been twenty-two SPRs on the upper level, and twenty-seven on the ground floor.

If that information had been in her head earlier, she would have turned the place upside-down to find that missing fiftieth robot. She would have found this one, the crucial one, much sooner.

Not that this one had been overlooked by anyone except Fredda. Gallingly enough, search teams had even logged in the location of this one two hours ago, but they had not examined it closely. What was one more shot-up robot in a building that was full of them?

She wanted to dive right in, to take this robot apart and find the clues, the proofs, she knew were inside it. But she resisted. Suppose she set to work now and smudged a fingerprint or something? No, thank you. There was no point in making any more mistakes.

It had been frustrating enough to have that imaginary door in the integrator simulation close on her face. To track the suspect this far and then come up with nothing-that would be slamming into a wall. It was starting to dawn on her just how much patience police work involved.

So, do it right, do it carefully. The clues in this room might be the core of the case. Don't ruin them. Let the robots do their job first. Then she could do hers.

"Donald," Fredda said. "I want you to call in a full team of Crime Scene robots. I want this robot and this entire room-and all the storage closets-scanned down to the maximum resolution. Our friend Mr. Pale-man was hiding in here, and he must have left some traces."

"That is by no means certain," Donald said. "It would be most useful, but we cannot count on it."

"But he must have left something behind," Fredda protested. "A bit of hair, a fingerprint, something. " Or was it possible that he could have left no trace at all behind? Fredda suddenly realized just how little she knew about the sort of clues she was counting on the robots to find.

"It is possible the Crime Scene team will find something," Donald said, "but bear in mind that if our suspect took a few simple precautions there would be nothing for us to find. "

Precautions? Fredda was suddenly confident of her ground. Forensics and clues she did not know about, but people she understood. She already had a pretty solid feel for Pale-man. Just watching him on the integrator had told her a lot. "This is not a man who takes all the simple precautions," she said. "This is a man who makes mistakes. If he hadn't acted so nervous when we first spotted him, if he hadn't made the slip of looking at his watch, we might have lost him in the shuffle. Instead he brought attention to himself. If he had at least pretended to be interested in the fight, we might have erased him from the image trail along with everyone else who came to watch it."

"And from those points you make the assumption that he would leave traces for us to find here?" Donald said.

"Oh, it's no assumption," Fredda said. "It's a certainty. He left something behind. " She had no logical reason for believing that, but logic was no more than a tool of reason, and far from the only tool at that. Gut reactions had their place as well.

"Trust me, Donald, " she said again, staring down at the burned-out wreck of the security robot. "This boy left a calling card."

Normalcy. The need for normalcy was painfully obvious. Caliban knew it was so-and yet, somehow, it was difficult to act on that knowledge.

Still, the demands of the day, the strictures of routine, helped a great deal. He had his job to do.

In theory, both Caliban and Prospero worked as field representatives for Fredda Leving, observing the behavior and actions of New Law robots, and reporting it to Dr. Leving's office. But their duties went far beyond those tasks. They were roving troubleshooters, tasked to find problems that slowed down work and resolve them.

In practice, Prospero was worse than useless in such work. He was far more likely to urge the New Law robots to set down their tools and make for Valhalla than he was to sort out a job-site scheduling dispute. These days, Prospero spent most of his time with his internal hyperwave system shut off so he would not be disturbed-or tracked. He liked to hide out from the world in an abandoned office somewhere under the streets of Limbo, reading and writing and studying, developing his philosophy.

Caliban, on the other hand, found that he was good at the job. He understood at least something of both the human and robotic point of view, and could often bring the two sides together. He had waded into the middle of any number of disputes between humans and New Law robots-and, for that matter, between robot and robot-struggling to find the common ground.

But there were times, be it confessed, when he wondered if New Law robots were worthy of freedom.

For the past two weeks, Caliban had been working with a team of New Law robots engaged in the refurbishment of an old windshifter force field coil, a massive, powerful, and intricate device. Its repair required careful planning and the coordination of many steps. The robot team was working without any direct human supervision, and every robot on the team was enthusiastic about the job.

Unfortunately, it seemed to Caliban that every New Law robot on the job had come up with a different better idea as to how the job should be done. There were so many ideas to sort through that it seemed unlikely that the job itself would ever be done.

It was up to Caliban to convince the robots that better was often the enemy of good, and that seeking perfection could mean accomplishing nothing. It was frustrating, at times, to see the trivial uses to which the New Law robots put their freedom. Fredda Leving had meant them to advance, to move in new directions-not waste time around a conference table, bickering once again over the most efficient way to retune a stasis suppression coil. He had agreed last night to come in well ahead of schedule this morning, in hopes of resolving a few of the issues at hand.

"Come, friends," Caliban said again. "Let us try again. Cannot we agree on this very minor point?"

"How can you dismiss maximized efficiency as a minor point?" Dextran 22 demanded.

"And what good is theoretical efficiency when your enhancement routines will leave the system unstable?" Shelkcas 6 asked.

"The enhancement routines are stable," Dextran replied, "or at least they would be in a properly normalized field environment. "

"Please!" Caliban interjected. "The normalization issue is resolved. There is no need to reopen it. Friends, once again we face the same old choice. We can solve the problem, or we can have the argument, but we cannot do both. Dextran, your enhancement system will work, and we can use it-so long as we do not press for greater than ninety-nine-plus percent efficiency. Is a half-percent improvement in efficiency truly worth major reliability degradation?"

"Perhaps not," Dextran admitted. "Perhaps the enhancement system alone will-"

"Caliban! Caliban!"

A voice, a human voice, and one he recognized, calling from the outer office. But what would bring Gubber Anshaw here? "Excuse me, friends. If we are resolved on this issue, perhaps you could move to the next point on the agenda while I step out."

Caliban rose, crossed the room, opened the door, and stepped through. There was Gubber, plainly agitated and upset. Caliban closed the door behind him. There was something in Dr. Anshaw's face that said his news would be best discussed in private.

"Caliban! Thank the stars you are here! What the devil are we going to do?"

"Do? Do about what?"

"Grieg, of course. Governor Grieg. They're sure to suspect Tonya. Caliban, you were there. You're a witness. She didn't do anything. You can tell them that."

"Dr. Anshaw, you confuse me," Caliban said, increasingly alarmed. All of Prospero's assurances that there would be no trouble, no danger, were clearly worth as little as Caliban had feared. "What about last night? What about the Governor?"

"Haven't you heard? Don't you know? Grieg is dead. He was killed last night just after-"

But Caliban was already gone before Anshaw could finish speaking. If things were uncertain enough that Anshaw feared Tonya Welton might be a suspect, then Caliban had no doubt whatsoever that he was in danger as well. He had to get away from where he could be found. Get away fast.

Shelabas Quellam was flushed with excitement. Governor. He was going to be Governor. Importance, power, respect. All his. All his. But there was so much he had to do to get ready. What to do first? A speech. Yes. He should write a speech for when he took over. Something along the lines of sorrow and courage, and the need to move forward-yes, that would be about the right approach.

He sat down at his comm console and settled in to start dictating-but then he noticed the status board was indicating all sorts of pending mail waiting for him in his office system-some of it official, and several days old.

Shelabas had never much bothered keeping close track of all his incoming correspondence. His robots read it for him, and wrote up summaries about the things he needed to deal with. But, come to think of it, he hadn't even checked their summaries in a while. He really ought to check it all now. There might be something in there of vital interest to the new Governor.

Shelabas Quellam scrolled the pending mail list-and then let out a little gasp. There was a letter from Grieg there, coded for Quellam's eyes only. But how could that be? But then he checked the dateline and saw that it had been waiting for him more than a week.

A week! Now that he thought of it, he could remember his robots advising him that there was urgent mail waiting for him in the system. He had no one but himself to blame for waiting this long to check.

His hand trembling, he worked the controls and saw Governor Chanto Grieg's face appear on the screen, looking confident, sure of himself, very much in charge. Not a printed letter, then, but a video record. There was something vaguely insulting about that. You sent video letters to those who might not have the patience to deal with the written word.

"Greetings to you, Legislator," Grieg's image said. It was plain to see that Grieg was speaking in formal mode, for the official record. This was not a personal letter-it was a policy statement. "It is with some reluctance that I came to the decision I must now report to you-and to you alone. As you know, I have long believed that the laws of succession to my office are excessively complex and could lead to great uncertainty in a crisis. For that reason, I named you, the man fated to succeed if I were removed from office by legal means, to be my successor if I were to die in office.

"As you are no doubt aware, there are currently moves afoot to impeach or recall me. As you may not be aware, Sheriff Kresh, Commander Devray, and Security Captain Melloy have all recently warned me of threats to my life. Thus, my removal from office, either by legal means or through my death, becomes increasingly more likely. I find that I can no longer treat it as a remote theoretical possibility, but as a probable event.

"I can no longer treat the principle of unified succession as being of paramount importance. While important in its own right, it cannot be allowed to stand in the way of the vital reforms, the diplomatic and economic policies upon which this government is embarked. It is my opinion that should you succeed me, the pressure for you to call early elections would be insurmountable. It is my further opinion that elections under such circumstances would almost certainly result in a government that would set policies likely to result in planetary disaster.

"For all of these reasons, I hereby inform you that I am withdrawing you from the Designation, in favor of a new name. After suitable discussion with the new Designate, I plan to announce the new name publicly. This I expect to transpire within a few weeks. Out of respect for you, for our long association, and for your office as President of the Legislative Council, I deemed it wise to provide you with early notification of this policy.

"With deep regret and apologies for any distress this decision might cause you, I will say good-bye."

The screen showed Grieg's authenticator seal, and then went blank.

Shelabas Quellam stared at the blank display in slack-jawed shock. He was not the Designate. He was not the Governor. He was nothing, nobody again.

But wait just a moment. Suppose Grieg had not named a new Designate before he died? As Shelabas recalled, the old Designation remained in force until the new Designation was made. For a mad instant, he considered erasing the letter, destroying all record of it, and declaring himself the Governor at once. But no. There would be copies placed with all the proper authorities. Destroying his copy could do no good-and would only throw suspicion on him-if he was not suspected of the crime already!

He stood up suddenly, his heart pounding. Grieg's murder! If no new Designate had been named, Shelabas Quellam was going to be a prime suspect the moment copies of Grieg's letter were found.

So Shelabas Quellam was not the Governor-and would not be, if Grieg had indeed named a new Designate.

Shelabas Quellam was simply a man who had a first-rate motive for the murder of the Governor.

And soon, very soon, everyone in the world was going to know it.

A half hour after running out on Anshaw, Caliban had reached a place of safety, a secret rustback escape office in an unused tunnel far below Limbo City Center. The office had an unregistered-and, it was to be hoped, untraceable-hyperwave set. He was all but certain no human knew about the hideout. It meant he could monitor the news reports without fear of being taken, and have a chance to think. The news nets were full of Grieg's death, and little else, and soon told him all he needed to know.

It required little imagination on Caliban's part to think he and Prospero might be suspects of some sort in the case-and with good reason. Caliban had been pursued by Alvar Kresh before, and he had no wish to repeat the experience. He had to call Prospero.

Caliban was the only robot on the planet of Inferno who was obliged to use a comm center in order to place a call. That was for the very good reason that every other robot had a full hyperwave comm system built in.

Caliban had been built for a laboratory experiment, and keeping him cut off from communications with the outside world had been part of the experiment. He could have arranged to have hyperwave equipment installed long ago, but Caliban had many very good reasons for not wishing to be turned off for even as brief a time as it would take to plug in the gear. There were too many things that could happen to him while he was switched off-too many things had happened to him when he had been switched off before. There were too many humans-and robots-who did not wish him well.

Normally, not having a hyperwave link was not much of a disadvantage. Right now, he needed desperately to speak with Prospero-and he did not know where Prospero's hidden study cell was. Prospero, too, had faced a number of threats in his day. But that did not matter. Prospero had long ago provided Caliban with a covert audio-only hyperwave link code that would connect to Prospero's office without being traceable.

He punched the comm code and spoke as soon as the connection was made. Prospero never spoke to anyone via hyperwave until he knew who it was. "Prospero, this is Caliban."

"Friend Caliban," Prospero's voice said through the speaker. "We must meet, most urgently."

"I agree the need is urgent," said Caliban. "This is a terrible crisis. But I feel that merely meeting will accomplish nothing."

"We had a plan as to what to do if things went wrong," Prospero said. "It is time for us to flee."

"We never expected things to go this wrong," Caliban objected. "I have no doubt your escape route would serve quite well under normal circumstances-but these are not normal circumstances. If we decamp now, we will have every human with a badge on the planet after us before nightfall. I have been tracked by Alvar Kresh before. I, for one, have no desire to be hunted again. It was only by the greatest good fortune that I survived the last time."

"The planet is large, and I have vast experience in covert movement," Prospero said.

"You have vast experience in arranging covert movement," Caliban said. "You yourself have never even been off the island of Purgatory. Besides, there is the question of corollary damage. If we were to flee, how many fugitive New Law robots will be destroyed as a consequence? How many of their hiding places will be exposed during the search for us?"

"There is something in what you say," Prospero said"

Also bear in mind that if we flee, we will be instantly perceived as the prime suspects in the Governor's death. That would do tremendous damage to the cause of the New Law robots. You have professed many times how nothing was more important to you than the rights-and the survival-of New Law robots. If we flee, we may well be dooming all New Law robots everywhere. "

"Your points are well taken," Prospero said. "But if we do not flee-what are we to do?"

"We must turn ourselves in. Submit to their questions. Cooperate. We will be exposing ourselves to grave danger, but, in my judgment, far less danger than in fleeing-and we will not be endangering the New Law robots."

Prospero did not reply for a moment. Caliban could not blame him for hesitating. The two evils they were forced to choose between were daunting, to say the least. At last, the New Law robot spoke. "Agreed," he said. "But how are we to do it? I do not wish to walk into a trap, or surrender myself to some SSS agent or Ranger who has been longing for the chance to blast a hole in a New Law robot."

Caliban had anticipated that question. He could see only one chance for them-a solution that might well be nothing more than a somewhat less elaborate form of suicide than fleeing Purgatory. "There is a robot," he said. "One that I believe we ought to contact. I believe it is the safest way. If he agrees to take us in without harming us, he will keep his word without trickery."

"Is this robot a friend of yours?"

"Oh, no," Caliban said. "On the contrary. If there is any robot in the universe I could count as an enemy, it is Donald 111."

"Kresh's robot? Why contact him?" Prospero asked.

"Because there are times," Caliban said, "when it is wiser to trust an enemy than a friend. " It was not the most tactful of remarks, under the circumstances. But Caliban felt no compunction about saying those words to his closest friend. After all, it was entirely possible that friend Prospero had gotten Caliban in trouble so deep that not even his deadliest enemy could save him.

Donald 111 banked the aircar slightly more to the east as he flew toward the agreed rendezvous point. He was flying faster than he would have dared if there were a human onboard, but time was short, and he could fly as fast as he wanted since there was no risk of First Law violation.

A scant twelve hours had passed since Grieg's body had been discovered, though it seemed even to Donald that a lifetime had passed since then.

Donald had need to hurry. He was due back at the Residence for the briefing session with Sheriff Kresh and the others. But this was an opportunity he could not forgo. Accepting the surrender of Caliban and Prospero surely took precedence.

He did not know what to make of it all, but that did not matter. He would meet their conditions and bring them in secretly, without consulting with anyone else. It was not necessary to understand why the two pseudo-robots wished to surrender to him, personally. It was enough to know they wished to surrender. It would be the greatest possible satisfaction to take the two of them into custody.

There. He was at the coordinates Caliban had specified. Donald circled once, low and slow, over the gravel-strewn open field, making sure those on the ground could see him. No surprises.

He brought the aircar into a hover thirty meters above the ground and then brought it down vertically, a slow, careful landing. Donald found himself moving with elaborate care, concentrating on the importance of not moving suddenly. Strange, very strange, to be considering the possibility that two robots-even pseudo-robots-might have lured him here as part of some trap. There was nothing to prevent them from greeting Donald with a blaster shot between the eyes.

Nor, Donald realized with surprise, was there anything preventing him from dispatching them. There was nothing at all in the Three Laws to prevent one robot from destroying another. Nothing at all about a robot wielding a blaster, or even firing it-so long as the robot did not fire at a human. Were the two of them out there, hiding in the scrubby line of trees that surrounded the clearing, wondering if he, Donald 111, were about to charge out of the aircar, guns blazing?

Absurd nonsense. Just because there was no prohibition against a thing, that did not render it plausible or sensible. A strange point to consider. It was just the sort of argument used to defend Caliban. Donald got up out of the pilot's seat, opened the hatch of the aircar, and stepped out onto the ground without giving way to any further nonsense.

There. At the edge of the clearing. The two pseudo-robots, Caliban and Prospero, the one tall and red, the other shorter and jet-black. They moved forward cautiously, and it did not escape Donald's notice that they both kept their hands in plain sight at all times.

Donald offered no greeting or salutation, but instead launched directly into formal procedure, using the formula they had negotiated via hyperwave link. " As per our agreement, I hereby remand both of you into the custody of the Hades Sheriff s Department, seconded to the Governor's Rangers. You are therefore submitted to the authority of the Sheriff and his duly designated deputies, as well as to the authority of the Governor's Rangers. So long as you do not resist such authority, and do not attempt to escape, you will not be harmed, punished, or destroyed without due process. " But what was due process in such a case? Donald did not know. Did anyone? And could he really make such promises when he had not informed Sheriff Kresh that he was making this arrest? "Do you understand?" he asked the two pseudorobots. It was a most strange moment. When else, in all of history, had one robot in effect arrested two other robots-or near-robots-for murder?

"I understand," Prospero said.

"As do I," said Caliban.

"Then come," Donald said, gesturing for them to go into the aircar. Caliban and Prospero walked past him, and through the aircar hatch. Donald followed behind, climbing aboard and closing the hatch behind him. The two of them had seated themselves in the passenger seats. Donald took his place at the controls and began preparations for takeoff.

It was over. He had them. He had to get back. He would be barely in time for the briefing as it was. He knew he should lift off immediately, without delay. But the empty formalism of taking them into custody was not enough. It was anticlimactic, unsatisfying. It did not answer the central question of the case. And Donald, as befitted a police robot, had a most powerful sense of curiosity.

He turned around in his seat and faced Prospero and Caliban. There was of course nothing, nothing at all to be read in their posture or their faces. Donald found that disturbing, for some reason. He had always been able to see something in a suspect's face. But then, suspects were humans, not robots.

Perhaps that was the trouble. These two were neither one nor the other. They were not true robots-but they were far from being human either. Something in between. Something less-and perhaps, Donald conceded, something more-than either.

But none of that mattered now. There was only one thing that Donald needed to know.

"Did you kill Chanto Grieg?" Donald asked, forcing the bald question out into the world. Kill. Kill. He was asking beings very like himself, very much like robots, beings built by the same Fredda Leving who had created Donald himself, if they had murdered a human being. The very thought of it was enough to disrupt his cognitive function for a moment. But Donald was a police robot, and used to thoughts of violence.

He knew that these two did not have the true robot's inability to lie, but that did not matter. He still needed to ask. He needed to hear the answer-true or false-in their voices. "Did you kill Chanto Grieg, or were the two of you part of any plot to kill him?"

"No," Caliban said, speaking for the two of them after a moment's hesitation. "We did not. We had nothing whatever to do with his death, and had no foreknowledge of it. We did not meet with him so we could kill him."

"Then what was your purpose?"

Caliban paused another moment, and looked again at Prospero before he spoke. And suddenly there was something readable in his manner, in his actions. It was the look of someone about to take a step from which there was no turning back, of someone launching themselves off into the abyss with no way of knowing what waited down below. "We met with him," Caliban said, "so we could blackmail him."