As he watched, one worker in particular caught his eye. The man was in a different outfit-dark blue overalls and yellow hard hat-and was carrying a roll of wire or cable over his shoulder. He emerged from a manhole near the back of the job site and stood, looking around, blinking. He pulled out a mobile phone and placed a call. Then he snapped it closed and wandered through the site and, instead of leaving, walked toward the building next door to the construction. He looked at ease, walking with a bounce in his step. Obviously he was enjoying whatever he was doing.

It was all so normal. That guy in the blue could have been Vetter thirty years ago. He could have been any one of Vetter's employees now.

The businessman began to relax. The scene made him feel a lot more at home-watching the guy in the blue uniform and the others in their Carhartt jackets and overalls, carrying tools and supplies, joking with one another. He thought of his own company and the people he worked with, who were like family. The older white guys, quiet and skinny and sunburned all of them, looking like they'd been born mixing concrete, and the newer workers, Latino, who chatted up a storm and worked with more precision and pride.

It told Vetter that maybe New York and the people he was doing this deal with were in many ways similar to his world and those who inhabited it.

Relax.

Then his eyes followed the man in the blue overalls and yellow hard hat as he disappeared into a building across from the construction site. It was a school. Sam Vetter noted some signs in the window.

Okay, he admitted, with a laugh, maybe New York is a little different from Scottsdale, after all.

RHYME CONTINUED TO look over the evidence, trying desperately to find, in the seemingly unrelated bits of metal and plastic and dust that had been collected at the scenes, some connection to spark his imagination and help Sachs figure out where exactly Galt had rigged the deadly cable to the water line running through Morningside Heights and Harlem.

If that's in fact what he'd done.

Spark his imagination… Bad choice of word, he decided.

Sachs continued to search Morningside Park, looking for the spliced wire running from the transmission cable to the pipes. He knew she'd be uneasy-there was no way to find the wire except to get close to it, to find where it had been attached to the water pipes. He recalled the tone of her voice, her hollow eyes as she'd described the shrapnel from the arc flash yesterday, peppering Luis Martin's body.

There were dozens of uniformed officers from the closest precinct, clearing Morningside Park and the buildings in the vicinity of the water pipe project. But couldn't the electricity follow a cast-iron pipe anywhere? Couldn't it produce an arc flash in a kitchen a mile away?

In his own kitchen, where Thom was now standing at the sink?

Rhyme glanced at the clock on his computer screen. If they didn't find the line in sixty minutes they'd have their answer.

Sachs called back. "Nothing, Rhyme. Maybe I'm wrong. And I was thinking at some point the line has to cross the subway. What if he's rigged it to hit a car? I'll have to search there too."

"We're still on the horn with Algonquin, trying to narrow it down, Sachs. I'll call you back." He shouted to Mel Cooper, "Anything?"

The tech was speaking with a supervisor in the Algonquin control center. Following Andi Jessen's orders, he and his staff were trying to find if there had been any voltage fluctuation in specific parts of the line. This might be possible to detect, since sensors were spaced every few hundred feet to alert them if there were problems with insulation or degradation in the electric transmission line itself. There was a chance they could pinpoint where Galt had tapped into the line to run his deadly cable to the surface.

But from Cooper: "Nothing. Sorry."

Rhyme closed his eyes briefly. The headache he'd denied earlier had grown in intensity. He wondered if pain was throbbing elsewhere. There was always that concern with quadriplegia. Without pain, you never know what the rebellious body's up to. A tree falls in the forest, of course it makes a sound, even if nobody's there. But does pain exist if you don't perceive it?

These thoughts left a morbid flavor, Rhyme realized. And he understood too that he'd been having similar ones lately. He wasn't sure why. But he couldn't shake them.

And, even stranger, unlike his jousting with Thom yesterday at this same time of day, he didn't want any scotch. Was nearly repulsed by the idea.

This bothered him more than the headache.

His eyes scanned the evidence charts but they skipped over the words as if they were in a foreign language he'd studied in school and hadn't used for years. Then they settled on the chart again, tracing the flow of juice from power generation to household. In decreasing voltages.

One hundred and thirty-eight thousand volts…

Rhyme asked Mel Cooper to call Sommers at Algonquin.

"Special Projects."

"Charlie Sommers?"

"That's right."

"This is Lincoln Rhyme. I work with Amelia Sachs."

"Oh, sure. She mentioned you." In a soft voice he said, "I heard it was Ray Galt, one of our people. Is that true?"

"Looks that way. Mr. Sommers-"

"Hey, call me Charlie. I feel like I'm an honorary cop."

"Okay, Charlie. Are you following what's happening right now?"

"I've got the grid on my laptop screen right here. Andi Jessen-our president-asked me to monitor what's going on."

"How close are they to fixing the, what's it called? Switchgear in the substation where they had that fire?"

"Two, three hours. That line's still a runaway. Nothing we can do to shut it down, except turn off the switch to most of New York City… Is there anything I can do to help?"

"Yes. I need to know more about arc flashes. It looks like Galt's spliced into a major line, a transmission level line, and hooked his wire to the water main, then-"

"No, no. He wouldn't do that."

"Why not?"

"It's a ground. It'd short out the instant it touched."

Rhyme thought for a minute. Then another idea occurred to him. "What if he was just hinting at tapping into the transmission line? Maybe he actually rigged a smaller trap, someplace else. How much voltage would you need for an arc?"

"A hundred and thirty thousand is your arc flash of mass destruction but, sure, you can have one with a lot less juice. The key is that the voltage exceeds the capacity of the line or terminal that's carrying it. The arc jumps from that to another wire-that's phase to phase. Or to the ground. Phase to ground. With house current, you'll get a spark but not an arc flash. That's at most about two hundred volts. When you're closer to four hundred, yes, a small arc is possible. Over six hundred, it's a strong possibility. But you're not going to see any serious length until you get into medium to high voltages."

"So a thousand volts could do it?"

"If the conditions were right, sure."

Rhyme was staring at the map of Manhattan, focusing on where Sachs was at the moment. This news exponentially increased the number of places where Galt might have planned his attack.