Rhyme examined some silvery flecks on his computer screen. “Metal. Ground or shaved off of something. Gas it. Let’s find out for certain.”

Cooper did.

“Petrochemical,” he answered. “Crudely refined, no additives . . . There’s iron with traces of manganese, silicon, and carbon.”

“Wait,” Rhyme called. “Any other elements—chromium, cobalt, copper, nickel, tungsten?”

“No.”

Rhyme gazed at the ceiling. “The metal? It’s old steel, made from pig iron in a Bessemer furnace. If it were modern it’d have some of those other materials in it.”

“And here’s something else. Coal tar.”

“Creosote!” Rhyme cried. “I’ve got it. The Dancer’s first big mistake. His partner’s a walking road map.”

“To where?” Sachs asked.

“To the subway. That grease is old, the steel’s from old fixtures and tie spikes, the creosote’s from the ties. Oh, and the fragment of tile is from a mosaic. A lot of the old stations were tiled—they had pictures of something that related to the neighborhood.”

Sachs said, “Sure—the Astor Place station’s got mosaics of the animals that John Jacob Astor traded.”

“Grouted porcelain tile. So that’s what the Dancer wanted him for. A place to hide out. The Dancer’s friend’s probably a homeless druggie living in an abandoned siding or tunnel or station somewhere.”

Rhyme realized that everyone was looking at a man’s shadow in the doorway. He stopped speaking.

“Dellray?” Sellitto said uncertainly.

The dark, somber face of Fred Dellray was focused out the window.

“What is it?” Rhyme asked.

“Innelman’s what it is. They stitched him up. Three hundred stitches they gave him. But it was too late. Lost too much blood. He just died.”

“I’m sorry,” Sachs said.

The agent lifted his hands, long sticklike fingers raised like spikes.

Everyone in the room knew about Dellray’s longtime partner—the one killed in the Oklahoma City federal building bombing. And Rhyme thought too of Tony Panelli—’napped downtown a few days ago. Probably dead by now, the only clue to his whereabouts the grains of curious sand.

And now another of Dellray’s friends was gone.

The agent paced in a threatening lope.

“You know why he got cut, don’t you—Innelman?”

Everyone knew; no one answered.

“A diversion. That’s the only reason in the world. To keep us off the scent. Can you believe that? A fuckin’ di-version.” He stopped pacing abruptly. He looked at Rhyme with his frightening black eyes. “You got any leads at all, Lincoln?”

“Not much.” He explained about the Dancer’s homeless friend, the drugs, the hidey-hole in the subway. Somewhere.

“That’s it?”

“Afraid so. But we still have some more evidence to look at.”

“Evidence,” Dellray whispered contemptuously. He walked to the door, paused. “A distraction. That’s no fucking reason for a good man to die. No reason at all.”

“Fred, wait . . . we need you.”

But the agent didn’t hear, or he ignored Rhyme if he did. He stalked out of the room.

A moment later the door downstairs closed with a sharp click.