Noble continued, "The basic scenario is our UNSUB got into one of the power company's substations and ran a wire outside the building."

" 'Unknown subject' singular?" Rhyme asked.

"We don't know yet."

"Wire outside. Okay."

"And then got into the computer that controls the grid. He manipulated it to send more voltage through the substation than it was meant to handle." Noble fiddled with cuff links in the shape of animals.

"And the electricity jumped," the FBI's McDaniel put in. "It was basically trying to get into the ground. It's called an arc flash. An explosion. Like a lightning bolt."

A 5,000 degree spark…

The ASAC added, "It's so powerful it creates plasma. That's a state of matter-"

"-that isn't gas, liquid or solid," Rhyme said impatiently.

"Exactly. A fairly small arc flash has the explosive power of a pound of TNT and this one wasn't small."

"And the bus was his target?" Rhyme asked.

"Seems so."

Sellitto said, "But they have rubber tires. Vehicles are the safest place to be in a lightning storm. I saw that someplace, some show."

"True," McDaniel said. "But the UNSUB had it all figured out. It was a kneeling bus. Either he was counting that the lowered step would touch the sidewalk or hoping somebody'd have one foot on the ground and one on the bus. That'd be enough for the arc to hit it."

Noble again twisted a tiny silver mammal on his cuff. "But the timing was off. Or his aim or something. The spark hit the sign pole next to the bus. Killed one passenger, deafened some people nearby, and dinged a few with glass, started a fire. If it'd hit the bus directly, the casualties would've been a lot worse. Half of them dead, I'd guess. Or with third-degree burns."

"Lon mentioned a blackout," Rhyme said.

McDaniel eased back into the conversation. "The UNSUB used the computer to shut down four other substations in the area, so all the juice was flowing through the one on Fifty-seven Street. As soon as the arc happened, that substation went offline, but Algonquin got the others up and running again. Right now about six blocks in Clinton are out. Didn't you see it on the news?"

"I don't watch much news," Rhyme said.

Sachs asked McDaniel, "The driver or anybody see anything?"

"Nothing helpful. There were some workers there. They'd gotten orders from the CEO of Algonquin to go inside and try to reroute the lines or something. Thank God they didn't go in before the arc happened."

"There was nobody inside?" Fred Dellray asked. The agent seemed a bit out of the loop and Rhyme guessed there hadn't been time for McDaniel to fully brief his team.

"No. Substations're mostly just equipment, nobody inside except for routine maintenance or repairs."

"How was the computer hacked?" Lon Sellitto asked, sitting noisily in a wicker chair.

Gary Noble said, "We aren't sure. We're running the scenarios now. Our white hat hackers've tried to run a mock terrorist scenario, and they can't get inside. But you know how it works; the bad guys're always one step ahead of us-techwise."

Ron Pulaski asked, "Anybody take credit?"

"Not yet," Noble replied.

Rhyme asked, "Then why terrorism? I'm thinking it's a good way to shut down alarms and security systems. Any murders or burglaries reported?"

"Not so far," Sellitto pointed out.

"A couple of reasons we think it's terrorists," McDaniel said. "Our obscure-pattern-and-relationship-profile software suggests so, for one thing. And right after it happened I had our people go through signals from Maryland." He paused, as if warning that nobody here should repeat what he was about to say. Rhyme deduced the FBI man was referring to the netherworld of intelligence-government snooping agencies that might not technically have jurisdiction in the country but who can maneuver through loopholes to keep on top of possible malfeasance within the borders. The National Security Agency-the world's best eavesdroppers-happened to be in Maryland. "A new SIGINT system came up with some interesting hits."

SIGINT. Signal intelligence. Monitoring cell phones, satellite phones, email… Seemed an appropriate approach when confronted with somebody using electricity to stage an attack.

"Picked up references to what we think is a new terror group operating in the area. Never cataloged before."

"Who?" Sellitto asked.

"The name starts with 'Justice' and has the word 'for' in it," McDaniel explained.

Justice For…

Sachs asked, "Nothing else?"

"No. Maybe 'Justice For Allah.' 'Justice For the Oppressed.' Anything. We don't have a clue."

"The words in English, though?" Rhyme asked. "Not Arabic. Or Somali or Indonesian."

"Right," McDaniel said. "But I'm running multi-language and -dialect monitoring programs on all communications we can pick up."

"Legally," Noble added quickly. "That we can pick up legally."

"But most of their communications take place in the cloud zone," McDaniel said. He didn't explain this.

"Uhm, what's that, sir?" Ron Pulaski asked, a variation of what Rhyme was about to, though in a much less deferential manner.

"Cloud zone?" the ASAC responded. "The phrase comes from the latest approach to computing-where your data and programs are stored on servers elsewhere, not on your own computer. I wrote an analysis paper on it. I'm using the term to mean new communications protocols. There's very little standard cell phone and email use among the negative players. People of interest are exploiting new techniques, like blogs and Twitter and Facebook, to send messages. Also embedding codes in music and video uploads and downloads. And personally I think they've got some new systems altogether, different types of modified phones, radios with alternative frequencies."

The cloud zone… Negative players.

"Why do you think 'Justice For' is behind the attack?" Sachs asked.

"We don't necessarily," Noble said.

McDaniel filled in, "Just, there were some SIGINT hits about monetary dispersals over the past few days and about some movement of personnel and the sentence 'It's going to be big.' So when the attack happened today, we thought, maybe."

"And Earth Day's coming up," Noble pointed out.

Rhyme wasn't exactly sure what Earth Day was-and didn't have an opinion about it one way or the other, except recognizing with some petulance that it was like other holidays and events: crowds and protesters clogging the streets and depleting the resources of the NYPD, which he might otherwise need to run cases.

Noble said, "Might be more than a coincidence. Attack on the grid the day before Earth Day? The President's taking an interest."

"The President?" Sellitto asked.

"Right. He's at some renewable energy summit outside of D.C."

Sellitto mused, "Somebody making a point. Ecoterror."

You didn't see much of that in New York City; logging and strip-mining weren't big industries here.

" 'Justice For the Environment' maybe," Sachs suggested.

"But," McDaniel said, "there's another wrinkle. One of the SIGINT hits correlated 'Justice For' with the name Rahman. No family name. We've got eight unaccounted-for Rahmans on our Islamist terror watch list. Could be one of them, we're thinking, but we don't know which one."

Noble had abandoned the bears or manatees on his cuffs and was now playing with a nice pen. "We were thinking, at Homeland, that Rahman could be part of a sleeper cell that's been here for years, maybe from around the time of Nine-eleven. Staying clear of an Islamist lifestyle. Sticking with moderate mosques, avoiding Arabic."

McDaniel added, "I've got one of my T and C teams up from Quantico."

"T and C?" Rhyme asked, peeved.

"Tech and Communications. To run the surveillance. And warrant specialists to get taps if we need them. Two DOJ lawyers. And we're getting two hundred extra agents."