Kathryn Dance gave a laugh. “You know that?”

Sellitto said, “Oh, Lincoln used to wander around the city collecting everything he could find for his evidence databases. . . . Must’ve been fun going out to dinner with you, Linc. You bring test tubes and bags with you?”

“My ex could tell you all about it,” Rhyme replied with an amused grunt. His attention was on the black spots of tar. “I’ll bet he’s been checking out another victim from a place that’s getting a new roof.”

“Or maybe they’re reroofing his place,” Cooper offered.

“Doubt he’s spending time enjoying cocktails and the sunset on his own roof in this weather,” Rhyme replied. “Let’s assume it’s somebody else’s. I want to find out how many buildings are being reroofed right now.”

“There could be hundreds of them, thousands,” Sellitto said.

“Probably not in this weather.”

“And how the hell do we find them anyway?” the rumpled detective asked.

“ASTER.”

“What’s that?” Dance asked.

Rhyme recited absently, “Advanced Spaceborne Thermal Emission and Reflection Radiometer. It’s an instrument and data package on the Terra satellite—a joint venture between NASA and the Japanese government. It captures thermal images from space. Orbits every . . . what, Mel?”

“About ninety-eight minutes. But it takes sixteen days to cover the entire Earth.”

“Find out when it was over New York most recently. I want thermal images and see if they can delineate heat over two hundred degrees—I imagine tar’s at least that temperature when it’s applied. Should narrow down where he’s been.”

“The whole city?” Cooper asked.

“He’s hunting in Manhattan, looks like. Let’s go with that first.”

Cooper had a lengthy conversation then hung up. “They’re on it. They’ll do their best.”

Thom showed Dennis Baker into the town house. “No other witnesses around the florist’s workshop,” the lieutenant reported, pulling off his coat and gratefully accepting a cup of coffee. “We searched for an hour. Either nobody saw anything or has the guts to admit they did. This guy’s got everybody spooked.”

“We need more.” Rhyme looked at the diagram that Sachs had sketched of the scene. “Where was the SUV parked?” he asked.

“Across the street from the workshop,” Sachs replied.

“And you searched the spot where it was parked.” It wasn’t a question. Rhyme knew she would have. “Any cars in front or behind it?”

“No.”

“Okay, he runs to the car, his partner drives to the closest intersection and turns, hoping to get lost in the traffic. He won’t break any laws so he’ll make a nice, careful—and sharp—turn, staying in his lane.” Like speed bumps and sudden braking, sharp, slow turns often dislodge important trace from treads of tires. “If the street’s still sealed off, I want a team from Crime Scene to sweep up everything at the intersection. It’s a long shot but I think we have to try.” He turned to Baker. “You just left the scene, right? About ten, fifteen minutes ago?”

“About that,” Baker replied, sitting and stretching as he downed his coffee. He looked exhausted.