And the pimps and the dealers would leave him alone, pegging him as innately conservative. Not up for much, and careful with his credit when he was.

The way I figured it later, they must have amputated part of his left thumb, somewhere behind the first joint, replacing it with a prosthetic tip, and cored the stump, fitting it with a spool and socket molded from one of the Ono-Sendai diamond analogs. Then they'd carefully wound the spool with three meters of monomolecular filament.

Molly got into some kind of exchange with the Magnetic Dog Sisters, giving me a chance to usher Ralfi through the door with the gym bag pressed lightly against the base of his spine. She seemed to know them.

I heard the black one laugh.

I glanced up, out of some passing reflex, maybe because I've never got used to it, to the soaring arcs of light and the shadows of the geodesics above them. Maybe that saved me. Ralfi kept walking, but I don't think he was trying to escape. I think he'd already given up. Probably he already had an idea of what we were up against.

I looked back down in time to see him explode.

Playback on full recall shows Ralfi stepping forward as the little tech sidles out of nowhere, smiling. Just a suggestion of a bow, and his left thumb falls of. It's a conjuring trick. The thumb hangs suspended.

Mirrors? Wires? And Ralfi stops, his back to us, dark crescents of sweat under the armpits of his pale summer suit. He knows. He must have known.

And then the joke-shop thumb tip, heavy as lead, arcs out in a lightning Yo-yo trick, and the invisible thread connecting it to the killer's hand passes laterally through Ralfi's skull, just above his eyebrows, whips up, and descends, slicing the pear shaped torso diagonally from shoulder to rib cage. Cuts so fine that no blood flows until synapses misfire and the first tremors surrender the body to gravity.