"It would be a pleasure." Rhyme glanced up and saw Thom gesturing to him and pointing to the hallway.

"Commander, I have to go now."

"I'm grateful you contacted me, Captain. I will be in touch as soon as I learn anything. Even if it seems insignificant, I will absolutely call you."

THOM LED TRIM, energetic Assistant Special Agent in Charge Tucker McDaniel into the lab again. He was accompanied by an associate, spiffy and young and compensating, whose name Rhyme immediately forgot. He was easier to think of as the Kid, capital K, anyway. He blinked once at the quadriplegic and looked away.

The ASAC announced, "We've eliminated a few more names from the list. But there's something else. We've got a demand letter."

"Who from?" Lon Sellitto asked from an examination table, where he sat wrinkled as a deflated ball. "Terrorists?"

"Anonymous and unspecified," McDaniel said, pronouncing every syllable primly. Rhyme wondered if he disliked the man as much as he thought he did. Partly it was how he'd treated Fred Dellray. Partly it was just his style. And sometimes, of course, you just didn't need a reason.

Cloud zone…

The agent continued, "Sounds mostly like a crank, eco issues, but who knows what it's a front for."

Sellitto continued, "We sure it's him?"

After an apparently motiveless attack, it wasn't unusual for a number of people to take credit for it. And threaten to repeat the incident if some demands weren't met, even though they themselves had nothing to do with it.

McDaniel said in a stiff voice, "He confirmed details of the bus attack. Of course we checked that."

The condescension explained some of Rhyme's distaste.

"Who received it and how?" Rhyme asked.

"Andi Jessen. I'll let her give you the details. I wanted to get it to you as fast as possible."

At least the fed wasn't fighting a turf war. The dislike eased a bit.

"I've told the mayor, Washington and Homeland Security. We conferenced about it on the way over."

Though without our presence, Rhyme noted.

The fed opened his briefcase and took out a sheet of paper in a clear plastic envelope. Rhyme nodded to Mel Cooper, who, in gloved hands, removed the sheet and placed it on an examining table. First, he photographed it and an instant later the handwritten text appeared on the computer screens around the room: To Andi Jessen, CEO, and Algonquin Consolidated Power:

At around 11:30 a.m. yesterday morning there was an arc flash incident at the MH-10 substation on W 57 Street in Manhattan, this happened by securing a Bennington cable and bus bar to a post-breaker line with two split bolts. By shutting down four substations and raising the breaker limit at MH-10 an overload of close to two hundred thousand volts caused the flash.

This incident was entirely your fault and due to your greed and selfishness. This is typical of the industry and it is reprehensable. Enron destroyed the financial lives of people, your company destroys our physical lives and the life of the earth. By exploiting electricity without regard for it's consequences you are destroying our world, you insideously work your way into our lives like a virus, until we are dependent on what is killing us.

People must learn they do not need as much electricity as you tell them they do. You have to show them the way. You are to execute a rolling brownout across the New York City service grid today-reduce levels to fifty per cent of offpeak load for a half hour, starting at 12:30. If you don't do this, at 1 p.m. more people will die.

Rhyme nodded toward the phone and said to Sachs, "Call Andi Jessen."

She did and a moment later the woman's voice came through the speaker. "Detective Sachs? Have you heard?"

"Yes, I'm here with Lincoln Rhyme and some people from the FBI and the NYPD. They've brought the letter."

Rhyme heard exasperation and anger as the woman said, "Who's behind it?"

"We don't know," Sachs said.

"You have to have some idea."

McDaniel identified himself and said, "The investigation's moving along, but we don't have a suspect yet."

"The man in the uniform at the coffee shop yesterday morning, by the bus stop?"

"We don't have his identity. We're going through the list you gave us. But nobody's a clear suspect yet."

"Ms. Jessen, this is Detective Sellitto, NYPD. Can you do it?"

"Do what?"

"What he's asking for. You know, reduce the power."

Rhyme didn't see any problem playing games with the bad guys, if a little negotiation gave extra time to analyze the evidence or run surveillance on a terrorist. But it wasn't his call.

"This is Tucker again, Ms. Jessen. We strongly recommend against negotiating. In the long run, that just encourages them to up their demands." His eyes were on the large detective, who stared right back.

Sellitto persisted, "It could buy us some breathing room."

The ASAC was hesitating, perhaps debating the wisdom of not presenting a united front. Still he said, "I would firmly recommend against it."

Andi Jessen said, "It's not even an issue. A citywide fifty percent decrease below off-peak load? It's not like turning a dimmer switch. It would throw off the load patterns throughout the Northeast Interconnection. We'd have dropouts and blackouts in dozens of places. And we've got millions of customers with on-off systems that'd shut down cold with that drop in power. There'd be data dumps and resets'd go to default. You can't just turn them back on again; it would take days of reprogramming, and a lot of data would be lost altogether.

"But worse, some of the life-critical infrastructure has battery or generator backup, but not all of it. Hospitals have only so much and some of those systems never work right. People will die as a result of it."

Well, thought Rhyme, the writer of the letter had one point right: Electricity, and Algonquin and the power companies, have indeed worked their way into our lives. We're dependent on juice.

"There you have it," said McDaniel. "It can't be done."

Sellitto grimaced. Rhyme looked toward Sachs. "Parker?"

She nodded, and scrolled through her BlackBerry to find the number and email of Parker Kincaid in Washington, D.C. He was a former FBI agent and now a private consultant, the best document examiner in the country, in Rhyme's opinion.

"I'll send it now." She dropped into a chair in front of one of the workstations, wrote an email, scanned the letter then sent them on their way.

Sellitto snapped open his phone and contacted NYPD Anti-Terror, along with the Emergency Service Unit-the city's version of SWAT-and told them that another attack was planned for around 1 p.m.

Rhyme turned to the phone. "Ms. Jessen, Lincoln again. That list you gave Detective Sachs yesterday? The employees?"

"Yes?"

"Can you get us samples of their handwriting?"

"Everybody?"

"As many as you can. As soon as you can."

"I suppose. We have signed confidentiality statements from just about everybody. Probably health forms, requests, expense accounts."

Rhyme was somewhat skeptical of signatures as representative of handwriting. Though he was no document examiner, you can't be the head of a forensics unit without developing some knowledge of the subject. He knew that people tended to scrawl their names carelessly (very bad practice, he'd also learned, since a sloppy signature was easier to forge than a precise one). But people wrote memos and took notes in a more legible way, which was more indicative of how they wrote in general. He told this to Jessen, and she responded that she'd put several assistants on the job of finding as many nonsignature examples of handwriting as she could. She wasn't happy but seemed to be softening her position that an Algonquin employee couldn't be involved.