A subway station loomed and he descended the slushy stairs then caught a train south. In twenty minutes Billy was back at his workshop, in the shower, letting the hot water blast his skin as he scrubbed and scrubbed.

Then toweling off, dressing again.

He clicked on the radio. A short time later the news reported another attack by the ‘Underground Man’, which had struck him as a rather pathetic nickname. Couldn’t they come up with anything better?

Still no mention of Amelia Sachs or anybody else falling victim to a strychnine attack. Which meant that by either diligence or luck the crime scene people had missed getting stuck by the needle in Samantha’s purse.

Billy had known all along the Modification would be like a battle, with wins and losses on both sides. He’d succeeded with two victims. The police had had some victories too. This was to be expected – in fact, it had been anticipated. Now, he reflected, he had to be a bit more serious about protecting himself.

An idea occurred to him.

Surprisingly simple, surprisingly good.

The applicable Commandment for this situation would be: Know thine enemy. But know the friends and family of thine enemy too.

CHAPTER 38

‘Hell, Amelia, how bad is it?’ Sellitto asked.

He and Sachs were standing in parallel positions – hands on hips – looking down into the dusky parking garage beneath the Belvedere Apartments.

‘Bad,’ she muttered. She looked over the city schematic of this scene. She ran her finger over the parking area and the abandoned New York Central train tunnel. ‘Ruined. Gone. All of the evidence.’

Sellitto stamped his feet, presumably to warm them against the stabbing chill of the icy muck they stood in. Sachs had stamped too; it didn’t work. Just made her toes sting more.

She noted Bo Haumann nearby, on his mobile. The ESU commander disconnected and strode over to them. Nodded.

Sellitto asked, ‘Anything?’

The wiry, compact man, wearing a turtleneck under his shirt, strode forward. He rubbed a hand over his gray crew-cut hair. His eyebrows were frosty but he seemed completely unfazed by the cold. ‘He’s gone. Rabbited. Got a team into the tunnel from a manhole up the street. But even that’s useless. All they could say is “No trace of him.”’

Sachs gave a grim laugh. ‘No trace. In both senses of the word.’

Rhyme’s concern had proved warranted. By opening the fire department standpipe, Unsub 11-5 had managed to obliterate the crime scene with calculated efficiency. The perp had then slipped out through the doorway by which he’d gained access to the parking garage, leaving it open. Within minutes, the geyser of water had flooded the ground floor of the garage and cascaded through the door into the tunnel below – which was to have been the killing zone.