“How can you be so sure?” Kresh asked.

Fredda pointed to the blaster shots. “Look at the chest shot. Virtually identical to the shots on the bedroom robots. That was the one that killed it. ”

“So?” Kresh said.

“So look at the paint-melts. The melts from the two smaller shots overlap the death shot. The killer blasted the robot in the chest from close up, then he or she got artistic. Either the robot fell over or the killer knocked it over and then backed off to do the other shots from a greater distance after the robot was already down.”

“You’re right,” Kresh said. “I should have spotted that. ”

“Well, your weapons analysis people would have seen it sooner or later. I only saw it because I was looking for it.”

“Looking for it?” Kresh asked. “Why?”

“Because these robots were not shot because the killer needed them dead,” Fredda said. “They were shot because that was the fastest way to destroy the evidence of tampering. My guess is that there was some sort of gadget attached to the circuitry in the center of the chest, right under the central access panel. ”

Fredda realized she was still staring down at the dead robot. A shot just like the one that killed the other robots. Just like the one that killed Grieg. Grieg dead. Sweet stars in the sky, Chanto Grieg was dead. She shut her eyes, took a deep breath, and tried to pull herself together. This was not the time to grieve. Not when the whole planet was about to fall apart.

“Sir, Doctor, if I might interject?”

“Yes, yes, Donald,” Fredda said, collecting herself. “What-what is it?”

“The Crime Scene robots have just posted some initial results to the hyperwave datanet. It concerns weapons analysis that might have some bearing on all this.”

“What sort of results?” Kresh asked.

“Range, power, and sequence estimates, sir. ”

“What are those?” Fredda asked.

“Ways of determining various characteristics of the weapon that fired a given sequence of shots,” Donald said. “The energy front of a blaster shot widens out as it moves forward. Measuring the radius of the blaster wound or mark gives an indication of range. By combining measures of the intensity of the wound or mark with the range estimate, we can derive the power of the blaster during each shot. As blasters drain their power somewhat with each shot, the first shot tends to be the most powerful, with each subsequent shot less and less powerful.”

“It doesn’t always work, though,” Kresh said. “With a high-capacity power supply, the power fall-off from one shot to the next can be undetectable.”

“In the present case, sir, we are more fortunate. Preliminary analysis shows a pronounced power fall-off with every shot. ”

“All right, Donald,” Kresh said, a note of weary patience in his voice. “What’s the punchline?”

“The shot that killed Governor Grieg was indeed the first one fired. ”

“I’ll be damned,” Kresh said. “Score one for you, Dr. Leving. If he was shot first, then the robots had to be shut down already. No reason to shoot them unless there was something that needed hiding. Except most of the robots downstairs weren’t shot. Why not?”

“Maybe if I take a look at some of them, I can find out what the-the assassins were trying to hide,” Fredda said. She had an idea or two already, but she was not ready to say anything yet. Not until she had something more than a theory.

“I’ll leave you to that,” Kresh said. “There are certainly plenty of SPR robots for you to examine. I do appreciate your help. You’ve already done me a larger service than you know. However, there is another duty I must perform in the meantime. Donald, you’re with me.”

“Yes, sir. ” The short blue robot made a slight bow toward Fredda. “Dr. Leving, it is good to be working with you again, albeit under such grim and unpleasant circumstances.”

“Thank you, Donald, “ Fredda said. The robot and the policeman headed down the stairs toward their improvised command center. Fredda stood up and looked down at the ruined robot. What a waste, she thought. What a miserable, useless waste.

Alvar Kresh knew the evil moment could not be put off any longer. It was time to put in a call to Justen Devray of the Governor’s Rangers. Two hours had passed since Kresh had discovered the body. The one bright spot was that, having thought about it, he could see no jurisdictional reason to call Cinta Melloy or the SSS at all. So far, at least, this was strictly an Infernal affair.

No doubt sooner or later the SSS would get mixed up in it as well. Major investigations had a way of spreading out. But at least he did not have to deal with them now. As little as he trusted the Rangers at the moment, he trusted the SSS even less.

Kresh sat down at the portable comm station his team had set up and punched the call to Devray.

Fredda Leving stood in front of Sapper 23. The robot was still standing, even though its power had been cut. It, along with most of its fellows on the ground floor and a few on the upper floor, had simply stopped dead, instead of being shot with a blaster. Why?

It was an inert lump of metal, literally dead on its feet. Fredda pushed down on the release stud, and there was a click from inside the robot’s chest. Now she could open the panel.

Fredda, feeling awkward in her surgical gloves, and distracted by the Crime Scene Observer robot hovering over her shoulder, pressed down on the lower exterior stud that would pop open the front access panel, now that it was unlatched. Sapper 23 stared down at her, unseeing, unnerving her. Most robots had power-down controls in the back, with a simple access cover anyone could open. But that, clearly, would never do for a security robot. You had to be right in front of a Sapper, watching it watching you, and you had to open a panel it controlled before you could shut it off. Except this robot was already off-and that was not supposed to happen.

The access plate swung open and Fredda stepped back, allowing the tiny Crime Scene Observer robot to hover in and do a full surface scan of the interior before she touched anything. The CSO flitted down until it was directly in front of the access panel. It extruded a tiny probe and directed it over every surface of the panel’s interior. The probe moved rapidly, fussily over the interior. At last it beeped to indicate it had done the scan and then backed off. Something about its motions reminded Fredda of the hummingbirds that the Settlers had just introduced onto Purgatory.

Fredda’s tool kit was open on the table next to her. She pulled out a clip light and a defastening tool. She attached the light to the lip of the power access panel and then used the defastener to pop open the maintenance panel inside. She lifted out the panel and set it down on the table, then stepped back to let the CSO robot do its job.

The maintenance chamber’s interior was far more complex than the switch chamber, and it took Fredda a moment to find what she was looking for.

Or, more accurately, to confirm that what she was looking for was not there. But it had most decidedly left its mark.

She smiled and stepped back from the Sapper. “Get me a magnified scan of the entire exposed surface in there. Maximum definition. ”

The tiny robot moved in and set to work, and Fredda watched. It was a good first step. There were all the other robots to check, of course, and she would have to be careful, thorough. But she felt a bit of excitement, of pleasure, all the same. She was starting to see how they did it-whoever they were.

But that sensation of pleasure did not last long. Because then she remembered what they had done.

Justen Devray was at his desk, working on the Huthwitz case, when the call came. “Damnation, Kresh, why the devil did you wait two hours to tell me?” Justen Devray was angry, and felt he had the right to be. He glared at the comm screen, feeling dead tired, horrified, and angry all at once. But not surprised. Somehow, he did not feel the least bit surprised.