And there were no other solid leads.The phone call about the intruder had come from an anonymous source. A canvass of the area, to find witnesses who’d seen the intruder, had yielded nothing. Security video cameras in two nearby stores had recorded a thin man in dark coveralls, walking with his head down and carrying a briefcase. He’d diverted suddenly into the cul-de-sac. No image of his face, of course.

Mel Cooper had run an analysis on the bottle and found, naturally, only Rhyme’s and Thom’s fingerprints, not even those of a liquor store stocker or a Scottish distiller.

No other trace was on the bottle.

Sachs was now telling him, ‘Nothing significant, Rhyme. Except he’s an ace lock picker. No tool marks. Used a pick gun, I’m sure.’

Cooper was checking the contents of the evidence collection bags. ‘Not much, not much.’ A moment later, though, he did make a discovery. ‘Hair.’

‘Excellent,’ Rhyme said. ‘Where?’

Cooper examined Sachs’s notes. ‘It was by the shelf where he spiked the whisky.’

‘And very good whisky it used to be,’ Rhyme muttered. ‘But a hair. Good. Only: Is it his, yours, mine, Thom’s, a deliveryman’s?’

‘Let’s take a look.’ The tech lifted the hair from the tape roller and prepared a slide for visual observation in the optical microscope.

‘There a bulb?’ Rhyme asked.

Hair can yield DNA but generally only if the bulb is attached.

But this sample, no.

Still, hair can reveal other facts about the perp. Tox and drug profiles, for instance (hair retains drug-use info for months). And true hair color, of course.

Cooper focused the microscope and hit the button that put the image on the high-def monitor nearby. The fiber was short, just a bit of stubble.

‘Hell,’ Rhyme said.

‘What?’ Sachs asked.

‘Look familiar, anyone?’

Cooper shook his head. But Sachs gave a soft laugh. ‘Last week.’

‘Exactly.’

The hair hadn’t come from the unsub but from the City Hall murder case of the week before, the worker killed fighting with the mugger. The beard stubble. The victim had shaved just before he’d left the office.

This happened sometimes. However careful you were with evidence, tiny samples escaped. Oh, well.

The mass spectrum computer screen came alive. Cooper focused and said, ‘Got the toxin profile: tremetol. A form of alcohol. Comes from snakeroot. There wasn’t enough to kill you, unless you drank the whole bottle at once.’

‘Don’t tempt me,’ Rhyme said.

‘But it would have made you very, very sick. Severe dementia. Possibly permanent.’

‘Maybe he didn’t have time to inject the whole dosage into the bottle. You know, it’s the dosage that’s deadly, not the substance itself. We all ingest antimony and mercury and arsenic every day. But not in quantities that do us any harm. Hell, water can kill you. Drink enough too quickly and the sodium imbalance can stop your heart.’