I began to look for clothes, pulling open drawers with no luck. If this man had spent a lot of time here, why had he nothing to wear except what he had on? Why no photographs or personal mementos? What about books, catalogues for ordering cell lines, tissue cultures, reference material for infectious diseases? Most obvious of all, what had happened to the vehicle that had towed this? Who had driven off in it and when?

I stayed in the bedroom longer, the carpet black from blood that had been tracked through other rooms when we had removed the body. I could not smell or hear anything but air circulating in my suit as I paused to change my four-hour battery. This room, like the rest of the camper, was generic, and I pulled back the flower-printed spread, discovering the pillow and sheets on one side were wrinkled from having been slept on. I found one short gray hair, and collected it with forceps as I remembered that the dead man’s hair was longer and black.

A print of a seaside on the wall was cheap, and I took it down to see if I could tell where it had been framed. I tried the love seat beneath a window on the other side of the bed. It was covered in bright green vinyl, and on top was a cactus plant that had to be the only thing alive in the camper except for what was in the cage, the incubator and the freezer. I stirred the soil with my finger and it was not too dry, then I placed it on the carpet and opened up the love seat.

Based on cobwebs and dust, no one had been inside in many years, and I sifted through a rubber cat toy, a faded blue hat and a chewed-on corncob pipe. I did not sense that any of this belonged to the person who lived here now, or had even been noticed by him. I wondered if the camper had been used or in the family, and got down on my hands and knees and crawled around until I found the shot shell and the wad. These, too, I sealed inside an evidence bag.

Lucy was just sitting down at the laptop computer when I returned to the laboratory area.

“Screen saver password,” she said into her voice-activated microphone.

“I was hoping you’d get something difficult,” I said.

She was already rebooting and going into DOS. Knowing her, she would have that password removed in minutes, as I’d seen her do before.

“Kay,” Gallwey’s voice sounded inside my hood. “Got something good out here.”

I went down the steps, careful to keep my air line from tangling. He was in front of the camper, squatting by the area of the tongue where the VIN had been obliterated. Having polished the metal mirror-smooth with fine grit sandpaper, he was now applying a solution of copper chloride and hydrochloric acid to dissolve scarred metal and restore the deeply stamped number underneath that the killer thought he had filed away.