Alvar Kresh, roused in the middle of the night for the second night in a row, stood, watching the fire squad dousing the last of the flames. Sometimes he envied the fire department their robots. Fire fighters merely had to save people and property, pure and simple, exactly the sort of thing robots were meant to do.

Police had to apprehend felons-and sometimes struggle with them, or even injure them. Obviously those duties could not be done by robots, but it went deeper than that. Even for the most sophisticated police robots made, most jobs requiring unsupervised direct contact with suspects were impossible.

For the average criminal on Inferno, being able to manipulate a robot with clever orders and judicious lies was a vital job skill. Even Donald’s access to suspects had to be strictly limited and controlled. If he were left by himself, there was an irreducible risk that some gifted con artist would find a way to talk his way through the Three Laws and convince Donald to let him go.

Robots, in short, made lousy cops but great fire fighters.

Not that there was much even the best fire fighters in the universe could do to savethis building. These old warehouses were little more than storage sheds to keep low-value merchandise out of the sun. This one hadn’t even been made of fire-resistant material, an economy that was turning out to be unwise this evening. It had gone up like a torch. Now, not more than forty minutes after the fire started, no more than a half hour after the initial response of the fire brigade, the building was little more than a half-collapsed frame of girders under a pall of smoke.

But the fire chief had noted that the interior was filled with some very interesting artifacts indeed, and called in the Sheriff. The ruined remains of at least a half dozen robots along with a pile of empty liquor bottles and a few odds and ends left behind in what was no doubt a rather hasty retreat were enough to interest Kresh, sleep or no sleep. But the slightly singed remains of a Settler-issue laborer’s cap were all he really needed to see.

Kresh felt his hunter’s instinct come to the fore. Here he was, not an hour behind a mob of Settler robot bashers. Now they were using arson to cover their tracks, but it wasn’t going to work.

But hell, their timing made it rough. Didn’t he have enough on his ‘plate with the Leving assault? Damnation, hewould have to get two major cases at the same time. It was going to be hard to, handle both investigations at once, but so be it.

The last of the flames died under the jets of water, and the fire robots shut off their hoses and set to work on the cleanup. phase. At almost the same moment, Sheriff’s Department crime scene robots moved in on the ruined building. Tall, spindly robots built to poke and pry; other, subminiature units designed to get in close to watch for small details and two or three other subspecialized types swarmed in. Kresh stepped forward into the rubble of the ruined building and was not at all surprised when Donald moved to stop him.

“Sir,” Donald said, “I do not believe it is wise for you to enter the building. There is still danger from hot spots and from possible further collapse of the frame.”

“Look at the fire robots,” Kresh said gently. “None of them are trying to stop me. Therefore, the danger is minimal. They and you together will surely be protection enough if a hot spot does flare. Come, join me. We can investigate this together.”

“Yes, sir,” Donald said, a bit doubtfully.

Kresh stepped into the ruined building, pulled a handlight out of his pocket, and shone it down on the debris-covered floor. Waterlogged bits of the fallen ceiling, a slurry of ash and fire-quenching chemicals, pieces of robot left behind by the Settlers’ festivities-the place was a mess. No clue was going to jump out at him here. It was hard to imagine the crime scene and fire investigation observer robots being able to make much of anything out of it, either, but that was what they were good at. All right, then, leave them to do the job.

What washe good at? It was at times a rather depressing question, in the face of all the things his robots could do that he could not. But this time he knew an answer: He could think through the cracks and crevices of human psychology, specifically criminal psychology, putting himself inside his quarry’s head. Alvar Kresh knew how to think like whomever he was chasing. It had been observed in more than one culture that good cops had to know how to be good criminals.

All right, then,Kresh decided.Think the way thesecriminals were thinking. Part of the story was obvious. A bunch of drunken Settler laborers head out for a good time and, say, a chance to pay back the Ironhead goons. But maybe they didn’t even need that excuse. They meet here, or come here together. How? Aircar, presumably. They have to get into this part of town unnoticed and be ready to get out fast if the cops show up.

In and out, in and out. Then something goes wrong.Arson, arson, Alvar thought.Something didn’t.fit about it. And then he had it. The motive was defective. There was no logical reason to set a fire. It had not hidden the evidence-too many robot parts had survived. Indeed, the fire had signaled the authorities to respond. If the bashers had simply walked away from this abandoned warehouse, it might easily have been days, or weeks, before anyone looked in here.

So, an accident, then? Drunken Settlers, a random shot with a blaster into this firetrap of a building-had it happened that way?

And then what? Panic, Kresh decided. A rush for the exit, and the waiting aircar outside. Drunks. They were drunk, running to get out, maybe one or two of them in worse shape than the others. Maybe one or two who didn’t make it all the way to the car before the terrified driver took off.

In which case…

“Donald!” he said. “Order a squad of crime scene robots to start a sweep of the area around the warehouse, looking for stragglers.”

“Stragglers, sir?” Donald asked, straightening up from his searching.

“These Settlers left in a hurry. Suppose not all of them got into the aircar, and the driver was too drunk and too scared to count noses? Someone might have been left behind.”

“Yes, sir. I will pass the order.” Instantly a dozen of the crime scene robots broke off their work and set out to search the area. Donald bent back over and returned to his methodical scan of the warehouse floor.

Kresh watched the crime scene robots go and then got back to his thinking. A panicky exit. The doorway. A crush of bodies hurrying through it as the flames rose higher. Maybe people dropping things, leaving telltale items behind.

Kresh stood in the middle of the ruined structure and scanned the bent and twisted remains of the building’ s frame, judging where the entrance had been before the collapse. There, in the middle of the south wall. He picked his way through the rubble-strewn floor, moving slowly, carefully sweeping his light back and forth across as he moved. Yes, the robots would do better, but even if he missed something they later found, at least he would have a feel for where that something came from.

Slowly, carefully, he moved toward the wreckage of the doorway and through it. In this part of town, no one even bothered paving the sidewalks. Just outside the doorway was nothing but hard-packed dirt. There was a confused tangle of rather muddied footprints, perfectly unreadable to Kresh, though the imagery reconstruction computers might be able to do something with them. Kresh was careful not to walk over anything himself.

It was not footprints he was looking for, but the sort of thing a person might drop or lose in a panicky hurry. Something that might lead Kresh to a name, a person. A wallet or an ident card would be ideal, of course, but he hardly dared expect that. But there were a thousand lesser things, perhaps none of them as easy or obvious as a photo ID, but some of them no less certain in the end. A bottle that might reveal a fingerprint, a bit of cloth that might have been torn from a shirt and left behind on a roughened edge of the door frame, a bit of skin or a drop of dried blood from where someone got scratched or cut in the rush to escape a burning building. A hair, a broken fingernail, anything that could be typed and DNA-coded would do for Kresh.