Vincent's face was pale and sweaty, and his hand trembled as he swept his laser gun back and forth, searching for a target. "Come on, come on," he said hoarsely. "You're on my territory now. I'm ready for you."

Something pale flashed briefly at the corner of my eye. I snapped around, but it was already gone. It ap­peared again, just a glimpse of white in the shadows between two machines. It flashed back and forth, ap­pearing and disappearing in the blink of an eye, darting up and down the length of the hall. Glimmers of shim­mering white as fleeting as moonlight, but I thought I was beginning to make out an impression of a pale, haunted face. It moved in the shadows, never venturing out into the light. But it was gradually drawing nearer. Heading for us, or perhaps for the steel door behind us and the secret vulnerable heart of Prometheus Inc.

My first thought was that it had to be a ghost of some kind, maybe a poltergeist. Which would explain why the CCTV cameras hadn't been able to see anything. Ghosts could operate in science- or magic-dominated areas, provided their motivation was strong enough. In which case, Vincent needed a priest or an exorcist, not a private eye. I suggested as much to Vincent, and he shrugged angrily.

"I had my people do a full background check on this location before we began construction; and they didn't turn up anything. The whole area was supposed to be entirely free from magical or paranormal influences. That's why I built here. I'm the Mechanic, I build things. It's a talent, just like your talent for finding things, John. I don't know about ghosts. You're the ex­pert on these matters. What do we do?"

"Depends what the ghost wants," I said.

"It wants to destroy me! I would have thought that was obvious. What was that?"

The white figure was flashing in and out of the shad­ows, on every side at once, drawing steadily closer all the time.