“Check it against the vic’s. Do a scale count and medulla pigmentation comparison,” Rhyme ordered.

A moment later Cooper looked up from the ’scope. “It’s not hers, the Colfax woman’s.”

“Description?” asked Rhyme.

“Light brown. No kink so I’d say not Negroid. Pigmentation suggests it’s not Mongoloid.”

“So Caucasian,” Rhyme said, nodding at the chart on the wall. “Confirms what the wit said. Head or body hair?”

“There’s little diameter variation and a uniform pigment distribution. It’s head hair.”

“Length?”

“Three centimeters.”

Thom asked if he should add to the profile that the kidnapper had brown hair.

Rhyme said no. “We’ll wait for some corroboration. Just write down that we know he wears a ski mask, navy blue. Fingernail scrapings, Mel?”

Cooper examined the trace but found nothing useful.

“The print you found. The one on the wall. Let’s take a look at it. Could you show it to me, Amelia?”

Sachs hesitated then carried the Polaroid over to him.

“Your monster,” Rhyme said. It was a large deformed palm, indeed grotesque, not with the elegant swirls and bifurcations of friction ridges but a mottled pattern of tiny lines.

“It’s a wonderful picture – you’re a virtual Edward Weston, Amelia. But unfortunately it’s not a hand. Those aren’t ridges. It’s a glove. Leather. Old. Right, Mel?”

The technician nodded.

“Thom, write down that he has an old pair of gloves.” Rhyme said to the others, “We’re starting to get some ideas about him. He’s not leaving his FR prints at the scene. But he is leaving glove prints. If we find the glove in his possession we can still place him at the scene. He’s smart. But not brilliant.”

Sachs asked, “And what do brilliant criminals wear?”

“Cotton-lined suede,” Rhyme said. Then asked, “Where’s the filter? From the vacuum?”

The technician emptied the cone filter – like one from a coffee-maker – onto a sheet of white paper.

Trace evidence…

DAs and reporters and juries loved obvious clues. Bloody gloves, knives, recently fired guns, love letters, semen and fingerprints. But Lincoln Rhyme’s favorite evidence was trace – the dust and effluence at crime scenes, so easily overlooked by perps.

But the vacuum had captured nothing helpful.

“All right,” Rhyme said, “let’s move on. Let’s look at the handcuffs.”

Sachs stiffened as Cooper opened the plastic bag and slid the cuffs out onto a sheet of newsprint. There was, as Rhyme had predicted, minimal blood. The tour doctor from the medical examiner’s office had done the honors with the razor saw, after an NYPD lawyer had faxed a release to the ME.

Cooper examined the cuffs carefully. “Boyd & Keller. Bottom of the line. No serial number.” He sprayed the chrome with DFO and hit the PoliLight. “No prints, just a smudge from the glove.”

“Let’s open them up.”

Cooper used a generic cuff key to click them open. With a lens-cleaning air puffer he blew into the mechanism.

“You’re still mad at me, Amelia,” Rhyme said. “About the hands.”

The question caught her off guard. “I wasn’t mad,” she said after a moment. “I thought it was unprofessional. What you were suggesting.”

“Do you know who Edmond Locard was?”

She shook her head.

“A Frenchman. Born in 1877. He founded the University of Lyons ’ Institute of Criminalistics. He came up with the one rule I lived by when I ran IRD. Locard’s Exchange Principle. He thought that whenever two human beings come into contact, something from one is exchanged to the other, and vice versa. Maybe dust, blood, skin cells, dirt, fibers, metallic residue. It might be tough to find exactly what’s been exchanged, and even harder to figure out what it means. But an exchange does occur – and because of that we can catch our unsubs.”

This bit of history didn’t interest her in the least.

“You’re lucky,” Mel Cooper said to Sachs, not looking up. “He was going to have you and the medic do a spot autopsy and examine the contents of her stomach.”

“It would’ve been helpful,” Rhyme said, avoiding her eyes.

“I talked him out of it,” Cooper said.

“Autopsy,” Sachs said, sighing, as if nothing about Rhyme could surprise her.

Why, she isn’t even here, he thought angrily. Her mind’s a thousand miles away.

“Ah,” Cooper said. “Found something. I think it’s a bit of the glove.”

Cooper mounted a fleck on the compound microscope. Examined it.

“Leather. Reddish-colored. Polished on one side.”

“Red, that’s good,” Sellitto said. To Sachs he explained, “The wilder their clothes, the easier it is to find the perp. They don’t teach you that at the academy, bet. Sometime I’ll tell you ’bout the time we collared Jimmy Plaid, from the Gambino crew. You remember that, Jerry?”

“You could spot those pants a mile away,” the young detective said.

Cooper continued, “The leather’s desiccated. Not much oil in the grain. You were right too about them being old.”

“What kind of animal?”

“I’d say kidskin. High quality.”

“If they were new it might mean he was rich,” Rhyme grumbled. “But since they’re old he might’ve found them on the street or bought them secondhand. No snappy deductions from 823’s accessorizing, looks like. Okay. Thom, just add to the profile that the gloves are reddish kidskin. What else do we have?”

“He wears aftershave,” Sachs reminded him.

“Forgot that. Good. Maybe to cover up another scent. Unsubs do that sometimes. Write it down, Thom. What did it smell like again, Amelia? You described it.”

“Dry. Like gin.”

“What about the clothesline?” Rhyme asked.

Cooper examined it. “I’ve seen this before. Plastic. Several dozen interior filaments composed of six to ten different plastic types and one – no, two – metallic filaments.”

“I want a manufacturer and source.”

Cooper shook his head. “Impossible. Too generic.”

“Damn,” Rhyme muttered. “And the knot?”

“Now that’s unusual. Very efficient. See how it loops around twice? PVC is the hardest cord to tie and this knot ain’t going anywhere.”

“They have a knot file downtown?”

“No.”

Inexcusable, he thought.

“Sir?”

Rhyme turned to Banks.

“I do some sailing…”

“Out of Westport,” Rhyme said.

“Well, as a matter of fact, yeah. How’d you know?”

If there were a forensic test for location of origin Jerry Banks would turn up positive for Connecticut. “Lucky guess.”

“It isn’t nautical. I don’t recognize it.”

“That’s good to know. Hang it up there.” Rhyme nodded toward the wall, next to the Polaroid of the cellophane and the Monet poster. “We’ll get to it later.”

The doorbell rang and Thom disappeared to answer it. Rhyme had a bad moment thinking that perhaps it was Dr. Berger returning to tell him he was no longer interested in helping him with their “project.”

But the heavy thud of boots told Rhyme who had come a-calling.

The Emergency Services officers, all large, all somber, dressed in combat gear, entered the room politely and nodded to Sellitto and Banks. They were men of action and Rhyme bet that behind the twenty still eyes were ten very bad reactions to the sight of a man laid up forever on his back.

“Gentlemen, you’ve heard about the kidnapping last night and the death of the victim this afternoon.” He continued through the affirmative muttering, “Our unsub has another victim. We have a lead in the case and I need you to hit locations around the city and secure evidence. Immediately and simultaneously. One man, one location.”

“You mean,” one mustachioed officer asked uncertainly, “no backup.”

“You won’t need it.”

“All due respect, sir, I’m not inclined to go into any tactical situation without backup. A partner at least.”

“I don’t think there’ll be any firefights. The targets are the major chain grocery stores in town.”