The Watchmaker’s Hand

Sachs coughed, a snapping, painful sound. She discreetly lifted a tissue to her mouth once more. A fast glance. With yet another bout of irritation, she stuffed the wad away in her jeans pocket. A hit of oxygen, then she said, “He knew what he was doing. He’d have to calculate how much weight he’d need to remove from the counterweights to make the crane unstable. There’s this thing the foreman was telling me about. Moment. It’s—”

Rhyme said, “Moment equals force times distance. Expressed in units of newton-meters.”

Sellitto was nodding. “So he’s got a degree in engineering. Put that on the chart.”

“No,” Rhyme said dryly. “Put down that he stayed awake in high school science class. Everybody knows that formula.”

Lon Sellitto rolled his eyes. “No, not everybody... But there is one thing we do know.”

Rhyme and Sachs looked toward the detective.

“He’s in good shape. Climbing that.”

“No elevator?”

“No,” Sachs said. “Ladders.” She walked to the diagram the foreman had provided to Sellitto — a side view of the crane before it fell — and tapped various places as she spoke. “Up here, he got into the slewing room, where the turntable is. Then up another ladder to go out onto the top, then down another ladder to the jib on the back.”

Rhyme could see a flat walkway that ran to the rear. It ended at a three-foot-high barrier, on the other side of which was the counterweight trolley. Up to that point were handrails and cables so workers could hook on as fall protection. But beyond that he’d have to tightrope walk — or crawl — along a narrow track two hundred feet in the air to get to the counterweights.

He really would have wanted this crane to come down, going to that risk and effort.

Rhyme repeated his earlier comment. “We need to source the acid.”

Sachs said, “I’ll get some people at the lab in Queens on it.”

“Tell them to look for suppliers who sell thirty-two percent or higher concentrations. You can dilute it, but you can’t make it more concentrated, not without a lot of time and effort.”

She placed the call, and after some deep inhalations, began a conversation with an officer on the other end of the line. Mel Cooper continued to examine the evidence that Sachs and the technicians had collected. Cooper called out the results, which were discouraging. The soil samples from the routes the unsub probably took to get to the crane tower base all matched the dirt throughout the jobsite. What they wanted was soil that didn’t match, which meant it might, possibly, have been left by the unsub and, if unique and traceable, could lead to his house or hideout.

After Sachs disconnected her call, she asked, “The videos you’ve been going through? Anything?”

Rhyme scoffed. “Nothing. The damn cameras all point down, ground level.”

The security system was meant to capture thieves, not acrobats sabotaging equipment in the sky above the jobsite.

He glanced at a digital wall clock. Twenty-two hours till the next crane came down.

On one of the murder boards was a map of New York — all five boroughs. The city’s construction permits department had provided a list of all the tower cranes presently in use. Thom had helped out by marking them with red X’s.

Which of these would be next?

Sellitto received a text. He looked at the screen. “Crap. It’s the mayor. He wants an update.”

“You’ve been here the whole time, Lon. We’ve learned that the unsub uses acid whose source we have no clue about yet, that he didn’t leave any discernable body or other trace at the scene. We’re in the dark completely about race, age and build — other than that he’s got strong legs and a good sense of balance.”

“Then I’ll tell the mayor that. They just need a bone.” He read another missive and said, “Hoped that announcing it was intentional might bring out some witnesses. But nobody’s come forward.”

Not a surprise.

“And where’s Ron?” Rhyme asked, his voice edgy. “We need him here. Isn’t he done with the homicide scene yet? How long could it take?”

Though even as he asked the question he was aware of what he told his students. “You search until there’s nothing left to search for. One hour, ten, seventy-two.”

“Turns out there’s a little more to it. The kid’s got a big win. He may’ve linked it to Eddie Tarr.”

Well, this was interesting. The Dublin-born former industrial engineer who put his considerable skills to work making clever devices that destroyed the structures that equally clever men and women designed and built. Wanted in dozens of jurisdictions, the careful and reclusive Tarr reportedly lived off the grid somewhere in the Northwest. Was he here for a job or to collect in-person payment?

“He’ll be here, but I know he wants to run down a lead or two on Tarr.”

Rhyme and Sachs shared a look. He could see that she too was happy for their protégé. With this, the brass would be taking notice of him.