‘He’s got another agenda beyond murdering individuals – clearly it’s not to rob them, it’s not sexual. It may serve his purposes to put the whole city on edge. Everybody in New York’s going to be thinking twice about heading into basements and garages and laundry rooms and using back doors to their offices and apartments. Now, a few other points. First, if he’s truly been influenced by the Bone Collector, then he may think about targeting you personally, Lincoln. And Amelia. In fact, you all might be in danger. Second, he’s clearly an organized offender, as I said. And that means he’s been checking out his victims, or at least the kill sites, ahead of time.’

Rhyme said, ‘We’re going on that assumption.’

‘Good. And finally – if he were really a copycat he would have concentrated on the victim’s bones. But he’s obsessed with skin. It’s central to his goal. He could just as easily be injecting them with poison or making them drink it. Or for that matter stabbing people or shooting them. But he’s not. He’s obviously a professional artist – so every time he puts one of his designs on a body, he claims somebody else’s skin as his own.’

‘A skin collector,’ Pulaski said.

‘Exactly. If you can find out why he’s so fascinated with skin, that’s key to understanding the case.’ Rhyme heard another voice, indistinct, from the doctor’s office. ‘Ah, you’ll have to excuse me now. I’m afraid I have a session to get to.’

‘Thanks, Doctor,’ Sachs said.

After he disconnected, Rhyme told Pulaski to put Dobyns’s observations up on the chart.

Quasi-babble … but, Rhyme reluctantly admitted, it might be helpful.

He said, ‘We should talk to Pam. See if anybody’s contacted her about the Bone Collector.’

Sachs nodded. ‘Not a bad idea.’

Pam was now out of the foster system and living on her own in Brooklyn, not far from where Sachs kept her apartment. It seemed unlikely that the unsub would even know about her. Because Pam was a child at the time of the Bone Collector kidnapping, her name had never come up in the press. And Serial Cities hadn’t mentioned her either.

Sachs gave the young woman a call and left a message asking her to come over to Rhyme’s. There was something she wanted to discuss.

‘Pulaski. Get back to marble detail. I want to find where that stone dust came from.’

The doorbell buzzed. And Thom disappeared to answer it.