One by one I slid the cushions onto the floor and sprayed down the couch’s frame. The spaces between the cushions glowed. On the backrest appeared more swipes and smears, and on .the ceiling appeared a constellation of small, bright stars. It was on the old television that we got our first pyrophoric display of false positives, as metal around the dials and screen lit up and cable connecters turned the bluewhite of thin milk. There was nothing remarkable about the TV, only a few smudges that might be blood, but the floor directly in front of it, where Robyn’s body had been found, went crazy. The blood was so pervasive that I could see the edges of the parquet’s inlays and the direction of the wood fibers constituting the grain. A drag mark feathered out several feet from the densest concentration of luminescence, and nearby was a curious pattern of tangential rings made by an object with a circumference slightly smaller than a basketball.

The search did not end in the living room. We began to follow footprints. At intervals we were forced to turn on lights, mix more luminol, and move clutter out of the way, particularly in the linguistic landfill that once had been Robyn’s bedroom and now was where Professor Potter lived. The floor was several inches deep in research papers, journal articles, exams, and scores of books written in German, French, and Italian. Clothes were strewn about and draped over things so haphazardly it was as if a whirlwind had kicked up in the closet and created a vortex in the center of the room. We picked up as best we could, creating stacks and piles on the unmade double bed. Then we followed Waddell’s bloody path.

It led me into the bathroom, with Vander at my heels.

Shoe prints and smudges were scattered about the floor, and the same circular patterns that we had found in the living room fluoresced by the side of the bathtub. When I began spraying the walls, halfway up and on either side of the toilet, two huge handprints suddenly appeared. The video camera’s light floated closer.

Then Vander’s voice said excitedly, “Flip on the light.”

Potter’s powder room was, to say the least, as disreputably maintained as the rest of his domain. Vander almost had his nose to the wall as he scrutinized the area where the prints had appeared.

“Can you see them?”

” LJmm. Maybe barely.”

He cocked his head to one side, then the other, squinting. “This is fantastic. You see, the wallpaper is this deep blue design, so nothing much is going to show to the naked eye. And it’s plasticized or vinyl - a good surface for prints, in other words.”

“Jesus,” said Wesley, who was standing in the doorway of the bathroom. “The damn toilet doesn’t look like it’s been cleaned since he moved in. Hell, it’s not even flushed.”