As he searched, he was thinking of the question that had dogged them from the beginning: How had the Watchmaker gotten the hydrofluoric acid onto the counterweights?
They knew he was somewhere near the crane yesterday morning when it came down — because Garry Helprin, the operator, had seen his beige SUV nearby.
And that meant he was probably present somewhere on video too, captured when he made his way to the tower, climbed it and planted the device. The operator started work at 9:00 and probably would have seen an intruder make the climb, so the device was planted prior to that. But how much prior? He knew from the discovery in the wheel well of the jet at JFK airport that the Watchmaker had been in the country for only a few days, which at least set a limit on the footage to search. This still meant, though, that Rhyme had to scrub through hundreds of hours of video, from multiple sources. He had footage from seven cameras.
Five of these were private security cameras with fair to poor resolution. Two of them were better, being newer additions to the Domain Awareness System.
“Nothing,” Cooper muttered.
Rhyme glanced at the clock on the wall nearby.
9:14.
Then a look at the map and a fleeting thought: Which one is your target, Charles?
He returned to the screen and scrubbed more quickly, focusing on the night before and the morning of the attack.
But the only person climbing the crane tower, at any time before the incident, was Helprin, just before 9 a.m.
The cameras were blocked occasionally by trucks stopping at lights or making deliveries at the jobsite or to nearby office buildings and apartments. Of particular irritation were advertising trucks, flatbeds toting large billboards. Most were cigarette ads — forbidden on TV — and for medicines to treat maladies whose nature was not clear from the content. Also, a number of campaign ads. Two, Rhyme noted, were pushing for voters to cast a ballot for Marie Leppert, the cartel buster running against the man who was Rhyme’s own representative in Washington, former activist (and criminal) Stephen Cody.
At one point, a large black bird nearly slammed into the camera, startling him.
When no clear suspects were evident, Rhyme turned his attention to the spectators, aware that perps do indeed return to the scene of the crime occasionally. He took note in particular of those who had visited the site on two separate occasions, if he could find them.
The most curious of these was a small, hunched-over homeless man in a bizarre orange and brown hat, like a nineteenth-century soldier’s, and a dirty brown overcoat. Rhyme noticed him because of his odd costume, yes, but also because of the man’s obsessive interest in the site. He held a blue-and-white coffee cup to collect change, but wasn’t doing much solicitation. He actually walked right past a businessman offering him a bill. He moved around the perimeter until the fire department’s Biotox unit arrived to neutralize the acid and they cleared everyone away.
Rhyme saw that he returned a couple of hours later. Most of the construction crew had gone home, so he just walked onto the site.
He seemed to be looking for something. Scavenging for valuables? Probably. He’d found something; there was a glistening metal object in his hand. If he spent much time there, maybe he’d be somebody for Sachs to talk to. If he could be located.
The second person who visited the site twice was memorable only because he was a musician. He carried a pale blue-gray guitar case, the word “Martin” printed on the side. Rhyme had learned from an investigation years ago that this was one of the best acoustic brands in the world. The man holding it at the jobsite was of medium build, white and bearded, a dark baseball cap with no logo tugged down firmly on his head. He wore sunglasses. He was in a black leather jacket and blue jeans.
His first visit was an hour after the collapse, then he returned four hours later. Rhyme could not deduce the man’s purpose in being present. Unlike the homeless man, who was drawn to the wreckage, the musician was constantly scanning the crowds, as if he were planning to meet someone.
He made two circuits of the site on his second visit. Apparently not finding what or whom he sought, he turned and left. Rhyme could have captured an image, but the sunglasses and the low brim of the hat meant facial recognition wouldn’t work.
His presence, like that of the homeless man, was probably nothing. Coincidence.
He continued to scrub, three days ago, two, yesterday. Daytime. Nighttime. Nobody approached the base of the mast except the operator.
He reflected: You’d think they’d make an algorithm that could spot perps doing all kinds of things — like climbing tower cranes.
Algorithms. Computers, data...
A thought occurred: Today there was a new type of Edmond Locard’s “dust” in the criminalist’s world digital bits and bytes. The ones and zeros that could lead you to your suspect’s home or office as efficiently as soil samples and bloodstains.
Except not in this case.
He sighed and returned to the monitor, scrubbing through the near bird strike.
But wait...
He froze the playback and reversed, frame by frame.
The black thing filled the screen.
It wasn’t a bird.
“Mel. Is this what I think?”
The technician looked. “It is. A drone.” Cooper flew “unmanned ariel vehicles” as a hobby and knew them well.
The stopped image had caught two propellers in motion.
“Goddamn. That’s how he did it.”
Drones could not legally be flown in the city, but misdemeanors would be no deterrent to the Watchmaker.
“Would it be big enough to carry the payload?”
“A commercial model, yes.”
“They’re tracked aren’t they?”
“Right. FAA, the Bureau and Homeland Security. But the last two’re the most active.”
Rhyme instructed the phone, “Call Dellray.”
The FBI agent answered on the first ring.
“Lincoln.”
“Fred. The cranes. We think the Watchmaker might be placing the device on them with a drone. Mel says you and DHS track them.”
“Oh, yeah. We’re the boys ’n’ gals for you. Our Counterterror folk. They’re lookin’ for birds all. The. Time. I’ll patch you through to a buddy — still hiding out on the other side of the office, by the way. No end of trouble I’m givin’ them for that. Hold tight.”
Rhyme’s eyes drifted to the map of the cranes in the city. He was thinking back to the early hours of the morning. Lyle Spencer had returned from his visits to the towers that they’d decided were most likely to be the next target. He’d reported that the bases of the cranes were all well guarded.
With a drone, those precautions were useless.
Then a baritone voice sounded into the phone. “Mr. Rhyme. Special Agent Sanji Khan, Counterterror. How can I help?”
Rhyme explained that he believed the device used to sabotage the crane on the Upper East Side was put in place with a drone. “You monitor them, right?”
“We do. FAA and DHS too. We coordinate findings. Radar and RF — radio frequency. If there’s a UAV — unmanned ariel vehicle — anywhere, we get a location. GPS from the RF is best. Radar’s dicey in the city.”
“Have you had any alerts lately?”
“Alert? No.” Khan added, “There’s an algorithm that only scrambles a response if the thing is near a high-profile target — airports, government buildings, embassies, concert halls, parades, that sort of thing. If the flight’s under ten minutes and it’s a low-threat location, we just log the details and don’t go after anybody. Usually it’s somebody gets a birthday or Christmas present and starts playing with it without knowing the law.”