Sellitto grimaced. “Security lapse there . . .” He frowned. “Then you waited until Thom went shopping and followed him to the store.”

Renard further explained, “This is Manhattan. Because most people walk to grocery stores they can’t carry that much, so they shop frequently. Usually every day. I didn’t think it’d be long before your assistant went out to pick up dinner. That started the plan in motion.”

Thom looked him over, nodding. “And, yes, I did see you—near my cart.”

“I was buying some fruit. When you looked away, I hit the tomato with an insulin syringe. Tap water. It was easy to do. I practiced last night.”

“And that?” Rhyme was looking at the bag that held the contraband Sachs had collected outside Hector Velasquez’s social club.

“I did some internet research into prominent gangsters. I liked the idea of using Velasquez. The authorities had been after him for a long time but weren’t having any luck. I decided that if there was a chance he’d be implicated in a crime the evidence would be sent to you. You were nearby and you are, after all, the best forensic scientist in the city.”

Rhyme offered a grunt, drawing a smile from Sachs.

“I filled a baggie with powdered sugar and hid it under some towels in the grocery bag. I took a train up to Spanish Harlem and then called nine one one and reported a drug deal going down. I waited until two squad cars turned onto First Avenue then made it seem like I was walking away from Velasquez’s club. I pretended to panic. I tossed the bag and my phone and ran. By the time the cops got there, I was gone.”

He stretched back, long legs out. His shoes were a rich brown; they’d been polished to the point of near reflection.

“As for the burner?” He looked toward phone that had spurted the faux toxin. “I modified the vibrator so that when it activated, it cut through a little packet of sugar again. Botulinum is the only airborne poison that would be fatal in such a small quantity.”

“Goddamn smart,” Sellitto whispered. He frowned yet again and said to Rhyme, “If you didn’t know what his plan was, weren’t you worried that it really was an attack and the poison was real?”

“We agreed that when he made the move he’d tell me, or text me, the word ‘goodbye,’ which a real assassin’d never do.”

Renard clicked his tongue. “Unprofessional.” He then gazed at the parlor’s ceiling. “Now, I analyzed my plan afterward and decided if I were a real killer, I’d do several things differently. I would have used a real explosive charge in the drone and blown it up over the pond. To convince you that it really was the murder weapon and not a diversion. And I would have found a cutout—a third party—to pay for the safe house. As it is now, the owner of the place got a look at my face. Oh, and when I was finished, I would have burned the building down, destroyed all the evidence. And, of course, killed the owner.”