‘Good idea. Efficient: a task force to find “the second” in a book or something? You think that’s ever appeared before, Linc?’

‘First, Lon, aren’t air quotes a bit overused? More to the point: How’s this? Have them search for the words in famous quotes about crimes, killers, tattoos, underground New York. Tell them to be creative!’

Sellitto muttered, ‘All right. “The second”. And for the number – the numeral two – with “nd” as a suffix.’

‘Hm,’ Rhyme muttered, nodding. He hadn’t thought of that.

The bulky detective placed a call, rising and walking to the corner of the parlor, and a moment later began barking orders. He disconnected and wandered back.

‘Let’s keep going,’ Rhyme said to the others.

After more trace analysis Mel Cooper announced, ‘We’ve got several instances of benzalkonium chloride.’

‘Ah,’ Rhyme said. ‘It’s a quat. Quaternary ammonium. A basic institutional sanitizer, used mostly where there’s particular concern about exposure to bacteria and a vulnerable clientele. School cafeterias, for instance. On the board.’

Cooper continued, ‘Adhesive latex.’

Rhyme announced that the product was used in everything from bandages to construction work. ‘Generic?’

‘Yep.’

‘Naturally,’ Rhyme grumbled. Forensic scientists vastly preferred brand-name trace – it was more easily sourced.

The tech ran additional tests. After a few minutes he regarded the computer screen. ‘Good, good. Strong results for a type of stone. Marble. Specifically Inwood marble.’

‘What form?’ Rhyme asked. ‘Put it up on the screen.’

Cooper did and Rhyme found they were looking at dust and grains of various sizes, white, off-white and beige. The tech said, ‘Fractured. See the edge on that piece in the upper left-hand corner?’

‘Sure is,’ Rhyme offered. ‘Bake it!’

The tech ran a sample through the GC/MS. He announced, ‘We’re positive for Tovex residue.’

Sellitto said, ‘Tovex? Commercial explosive.’

Rhyme was nodding. ‘Had a feeling we’d find something like that. Used in blasting foundations out of rock. Given the trauma to the marble grains, our unsub picked up that trace at or near a construction site. Someplace where there’s a lot of Inwood marble. Call the city for blasting permits, rookie. And then cross-reference with the geological database of the area. Now, what else?’

The scrapings beneath Chloe Moore’s fingernails revealed no skin, only off-white cotton cloth and paper fibers.

Rhyme explained to Sellitto: ‘Chloe may’ve fought him and picked those up in the struggle. A shame she didn’t get a chunk of his skin. Where’s the DNA when you need it? On the board, and let’s keep at it.’