But the more he thought about it, the less likely it seemed. Rhyme figured Duncan had made up the story about the undelivered package to the Met just to get them focused on the museum. Somebody as careful as the Watchmaker wouldn’t leave the trail he did. He turned in Vincent, knowing the rapist would give up the church, where he’d left other museum brochures referring to the Mechanism. He mentioned it to Hallerstein and to Vincent as well. No, he was up to something else. But what? Kathryn Dance reviewed the interview tape again, several times, and decided that he might have been lying when he said he picked the supposed victims simply because their locations meant easy getaways.

“Which meant,” Rhyme told Dellray, “that he picked them for some other purpose. So, did they have anything in common?”

Rhyme had remembered something Dance learned about the first crime scene. Ari Cobb had said that the SUV was originally parked in the back of the alley but then the Watchmaker returned to the front to leave the body. “Why? One reason was that he needed to put the victim in a particular place. What was it near? The back door to the Housing and Urban Development building.”

Rhyme had then gotten the client list from the flooring company where he’d planted the fake fire extinguisher bomb and learned that they’d provided carpeting and tile for the HUD offices.

“I sent our rookie downtown to look around. He found a building across Cedar Street that was being renovated. The crews had tarred the roof a week ago, just before the cold spell. Flakes of tar matched those found on our perp’s shoes. The roof was a perfect place to check out HUD.”

This also explained why he’d poured sand on the ground at the crime scene and swept it up—to make absolutely certain they didn’t find trace that’d help anyone identify him later when he came back to assemble and arm the bombs.

Rhyme also found that the other victims had a connection to the building. Lucy Richter was being recognized there today, and she’d had the specially issued passes and IDs to get into all parts of the building. She also had a classified memo on security and evacuation procedures.

As for Joanne Harper, it turned out that she’d done the flower arrangements for the ceremony—a good way to smuggle something into the building.

“A bomb, I guessed. We got the mayor involved and he called the press, had them hold off on the story that we were evacuating HUD so the perps wouldn’t rabbit. But the device blew before the bomb squad could disarm it.” Rhyme shook his head. “Just hate it when good evidence blows up. You know how hard it is to lift prints off pieces of metal that’ve been flying through the air at thirty thousand feet a second?”

“How’dja get Miss Congeniality here?” Dellray asked, nodding at Charlotte.

Rhyme said dismissively, “That was easy. She was careless. If Duncan was fake, then the woman helping him at the first scene in the alley had to be fake too. Our rookie got all the tag numbers of cars in the vicinity of the alley off Cedar. The car the supposed sister was driving was an Avis, rented to Charlotte Allerton. We checked all the hotels in the city until we found her.”