"But why're you asking about arcs?" Sommers wondered.

"Because," Rhyme said absently, "Galt's going to kill somebody with one in less than an hour."

"Oh, did Galt's note say something about an arc?"

Rhyme realized that it didn't. "No."

"So you're just assuming that's what he'd do."

Rhyme hated the word "assumption" and all its derivatives. He was furious with himself, wondering if they'd missed something important. "Go on, Charlie."

"An arc is spectacular but it's also one of the least efficient ways to use electricity as a weapon. You can't control it very well, you're never sure where it's going to end up. Look at yesterday morning. I mean, Galt had a whole bus for a target and he missed… You want to know how I'd kill somebody with electricity?"

Lincoln Rhyme said quickly, "Yes, I very much would," and tilted his head to the phone to listen with complete concentration.

THOMAS EDISON INTRODUCED overhead transmission, those ugly towers, in New Jersey in 1883, but the first grid ran beneath the streets of Lower Manhattan, starting from his generating station on Pearl Street. He had a grand total of fifty-nine customers.

Some linemen hated the underground grid-the dark grid, as it was sometimes called-but Joey Barzan loved it down here. He'd been with Algonquin Power for only a couple of years but had been in the electrical trades for ten years, since he'd started working at eighteen. He'd worked private construction before joining the company, moving his way up from apprentice to journeyman. He was thinking of going on and becoming a master electrician, and he would someday, but for now he liked working for a big company.

And what bigger outfit could he find than Algonquin Consolidated, one of the top companies in the country?

A half hour earlier he and his partner had gotten a call from his troubleman that there'd been a curious fluctuation in power in the supply to a subway system near Wall Street. Some of the MTA lines had their own power plants, miniature versions of Algonquin's MOM. But this line, the one rumbling nearby right now, was powered purely by Algonquin juice. The company transmitted 27,500 volts from Queens to substations along the line, which stepped it down and converted it to 625 volts, DC, for the third rails.

A gauge in a nearby MTA substation reported that for a fraction of a second there'd been a dropout. Not enough to cause any disruption of subway service but enough to be concerned-considering the incident at the bus station early yesterday.

And, damn, an Algonquin employee was the one behind it. Ray Galt, a senior troubleman in Queens.

Barzan had seen arc flashes-everyone in the business had at one time or another-and the spectacle of the burning lightning, the explosion, the eerie hum was enough to make him promise himself he'd never take a chance with juice. PPE gloves and boots, insulated hot sticks, no metal on the job. A lot of people thought they could outthink juice.

Well, you can't. And you can't outrun it either.

Now-his partner up top briefly-Barzan was looking for anything that might've caused the current to dip. It was cool here and deserted, but not quiet. Motors hummed and subways shook the ground like earthquakes. Yep, he liked it here, among the cables and the smell of hot insulation, rubber, oil. New York city is a ship, with as much structure under the surface as above. And he knew all the decks as well as he knew his neighborhood in the Bronx.

He couldn't figure out what had caused the fluctuation. The Algonquin lines all seemed fine. Maybe-

He paused, seeing something that made him curious.

What is that? he wondered. Like all linemen, whether up top or in the dark grid, he knew his territory and at the dim end of the tunnel was something that wasn't right: A cable was spliced to one of the breaker panels feeding the subway system for no logical reason. And, instead of running down into the ground, to reach the subway, this went up and ran across the ceiling of the tunnel. It was well spliced-you judged a lineman's skill by how well he joined lines-so it'd been done by a pro. But who? And why?

He stood and started to follow it.

Then gasped in fright. Another Algonquin worker was standing in the tunnel. The man seemed even more surprised to run into somebody. In the dimness Barzan didn't recognize him.

"Hi, there." Barzan nodded. Neither shook hands. They were wearing PPE gloves, bulky-thick enough for live-wire work provided the rest of the dielectric was adequate.

The other guy blinked and wiped sweat. "Didn't expect anybody down here."

"Me either. You hear about the fluctuation?"

"Yeah." The man said something else but Barzan wasn't really listening. He was wondering what the guy was doing exactly, looking at his laptop-all linemen used these, of course, everything on the grid being computerized. But he wasn't checking voltage levels or switchgear integrity. On the screen was a video image. It looked like the construction site that was pretty much overhead. Like what you'd see from a security camera with good resolution.

And then Barzan glanced at the guy's Algonquin ID badge.

Oh, shit.

Raymond Galt, Senior Technical Service Operator.

Barzan felt his breath hiss from his lungs, recalling the supervisor that morning calling in all the linemen and explaining about Galt and what he'd done.

He now realized that the spliced cable was rigged to create another arc flash!

Be cool, he told himself. It was pretty dark down here and Galt couldn't see his face very well; he might've missed Barzan's surprised reaction. And the company and the police had made the announcement only a little while ago. Maybe Galt had been down here for the past couple of hours and didn't know the cops were looking for him.

"Well, lunchtime. I'm starving." Barzan started to pat his stomach and then decided that was overacting. "Better get back upstairs. My partner'll be wondering what I'm doing down here."

"Hey, take care," Galt said and turned back to the computer.

Barzan too turned to head toward the closest exit, stifling the urge to flee.

He should have given into it, he quickly realized.

The instant Barzan turned, he was aware of Galt reaching down fast and lifting something from beside him.

Barzan started to run but Galt was even faster and, glancing back, Barzan had only a brief image of a lineman's heavy fiberglass hot stick, swinging in an arc into his hard hat. The blow stunned him and sent him tumbling to the filthy floor.

He was focused on a line carrying 138,000v, six inches from his face, when the stick slammed into him once more.

AMELIA SACHS WAS doing what she did best.

Perhaps not best.

But doing what she loved most. What made her feel the most alive.

Driving.

Pushing metal and flesh to its limits, speeding fast along city streets, seemingly impossible routes, considering the dense traffic, human and vehicular. Weaving, skidding. When you drove fast, you didn't ease the vehicle along the course, you didn't dance; you pounded the car through its moves, you slammed and jerked and slugged.

These were called muscle cars for a reason.

The 1970 model year 428 Ford Torino Cobra, heir to the Fairlane, pushed out 405 horsepower with a nifty 447 foot pounds of torque. Sachs had the optional four-speed transmission, of course, which she needed for her heavy foot. The shifter was tough and sticky and if you didn't get it right you'd have adjustments aplenty, which might include flushing gear teeth out of the reservoir. It wasn't like today's forgiving six-speed syncromeshes made for midlife-crisis businessmen with Bluetooths stuck into their ear and dinner reservations on their mind.