Though it would be a very different life that his target would live in the future; perhaps the most disturbing symptoms of non-lethal white snakeroot poisoning were delirium and dementia. The man he was going to poison in a few moments would stay alive but become a raving madman for a long, long time.

Billy nonetheless had one regret: that his victim would be incapable of feeling the searing, unbearable nausea and gut pain that white snakeroot’s toxin caused. Lincoln Rhyme was numb to sensation below his neck. The vomiting, tremors and other symptoms would be unpleasant but not as horrific as in a person who had a fully functioning nervous system.

Billy now turned west down a cross street and entered a brightly lit Chinese restaurant, which was filled with the smells of garlic and hot oil. He made his way to the restroom, where, in a stall, he lost the hat and overcoat and dressed in coveralls.

Outside once more – unnoticed by diners or staff, he observed – Billy walked across the street and into the service alley that would lead to the back of Rhyme’s apartment.

The cul-de-sac was pungent – smelled a bit like the Chinese restaurant, now that he thought about it – but relatively clean. The ground was ancient cobblestones and patches of asphalt, dotted with slush and ice. Several Dumpsters sat well-ordered against brick walls. It seemed that several town houses, including Rhyme’s, and a larger apartment building backed onto this area.

Noting a video camera at the rear of Rhyme’s town house, he went about his faux business of checking electrical lines.

Ducking behind a Dumpster, as if searching for a troublesome bit of electrical wire conduit, Billy circumvented the camera and approached the door. He extracted the hypodermic that contained the snakeroot toxin from his toothbrush holder and slipped the syringe into his pocket.

Tremetol, a clear liquid, is an alcohol and would blend instantly with what Billy’s research had revealed was Rhyme’s favorite beverage – single-malt scotch. It would also be tasteless.

Billy’s palms sweated. His heart thudded.

For all he knew there might be ten armed officers inside, meeting with Rhyme at the moment. The alarm wouldn’t be on, not during the day, but he could easily be spotted lacing the bottle.

And possibly shot on the spot.

But the Modification, naturally, involved risk. What important missions didn’t? So, get on with it. Billy pulled out his phone, a prepaid model, untraceable, and pressed in a number.

Almost immediately he heard, ‘Police and fire. What’s your emergency?’

‘A man with a gun in Central Park! He’s attacking a woman.’

‘Where are you, sir?’

‘He’s got a gun! I think he’s going to rape her!’

‘Yes, sir. Where are you? Where exactly?’

‘Central Park West, about … I don’t know. It’s … uhm, okay, in front of Three Fifty Central Park West.’

‘Is anyone hurt?’