Cooper consulted a database. He said, “A Converse Con. Size ten and a half.”

Naturally, a very common sneaker. Impossible to trace to a single retail source from the tread alone. Rhyme knew this about the shoe, since he was the one who had created and still helped maintain the NYPD’s database of footwear.

Sachs’s attempt to lift tire treads had been, on the other hand, unsuccessful. Other cars and trucks had driven in about the same path as the kidnapper’s sedan, obliterating distinctive tread impressions.

Rhyme said, “I suppose we better ask. What else did the child have to say?”

Sachs described how the kidnapping had unfolded.

“A hood over the vic’s head. And he went limp?” Sellitto asked. “Suffocated?”

Rhyme said, “Pretty short period of time. Drugs maybe. Chloroform—a classic. You can also use homemade concoctions.”

“What color was the hood?” Cooper asked.

“Dark.”

“I’ve got a fiber here,” the tech added, looking at the evidence bag notation. “Cotton. Amelia, you rolled it up right next to where he left the noose.”

Rhyme looked at the monitor on which a tuft of fiber was displayed. He had a decision to make. The intact fiber could have important evidentiary value. Say they found a hood in the possession of a suspect; he could be linked to the crime if its fibers could be associated with this one (you didn’t say “matched”; only DNA and fingerprints actually matched).

That would be good for the prosecutor’s case at trial. But having the fiber in its present state didn’t get you any closer to discovering who the perp was and where he lived or worked. Cotton, though, was wonderfully absorbent and this tiny piece might hold very helpful clues. The problem was that they could be unlocked only with the gas chromatograph—an instrument that isolated and identified substances. And to analyze the fiber required that it be destroyed.

“Burn it, Mel. I want to know if there’s anything inside.”

The tech prepared the sample for the Hewlett-Packard. The whole process would take no more than twenty minutes.

In the meantime, Sellitto and Dellray checked in with their respective supervisors. There’d still been no ransom demands, and no CCTV in the area had recorded the incident or the car speeding away. Dellray then uploaded all the information they had to NCIC, the National Crime database, to see if similar incidents had been reported elsewhere. None.

Rhyme said, “Let’s get a chart going.”

Sachs pulled a whiteboard close and took a dry marker. “What do we call him?”

Often the month and day were used as a temporary nickname for an unknown subject. This perp would be UNSUB 920, for September 20.

But before they decided on a moniker, Cooper stirred and looked at the screen of the GC/MS computer. “Ah. You were right, Lincoln. The fiber—presumably from the hood—shows traces of chloroform. Also, olanzapine.”

“Knocky-out drug?” Dellray asked. “Roofie for kidnappers?”

Cooper was typing. “A generic antipsychotic. Serious stuff.”

“From our boy’s medicine cabinet? Or the vic’s?” Sellitto wondered aloud.