"Here's how the grid works in New York. One of the workers drew this for me, and it was helpful." Sachs pulled out a piece of paper on which was a diagram. She stepped to a whiteboard and, with a dark blue marker, transferred the writing.

Power Generation Plant or Incoming Supply (345,000v) v (through high tension cables)

Transmission Substation (steps 345,000v down to 138,000v) v (through area transmission lines)

Area Substation (steps 138,000v down to 13,800v) v (through distribution feeder lines)

1. Spot networks in major commercial buildings (steps 13,800v down to 120/208v), or

2. Street-level transformers (steps 13,800v down to 120/208v) v (through incoming service lines)

Households and offices (120/208v)

Sachs continued, "Now, MH-Ten, the substation on Fifty-seven, is an area substation. The line coming in was high voltage. He could've rigged the cable anywhere on an area transmission line but that's real tricky, I guess, because the voltage is so high. So he was working on the output side of the area substation, where the voltage is only thirteen thousand eight hundred."

"Phew," Sellitto muttered. " 'Only.' "

"Then when it was rigged he set the circuit breakers higher and flooded the station with incoming juice."

"And it blew," Rhyme said.

She picked up an evidence bag containing teardrop-shaped bits of metal. "And then it blew," she repeated. "These were all over the place. Like shrapnel."

"What are they?" Sellitto asked.

"Molten droplets from the bus sign pole. Blew them everywhere. Nicked the concrete and went right through the sides of some cars. The vic was burned but that's not what killed him." Her voice grew soft, Rhyme noticed. "It was like a big shotgun blast. Cauterized the wounds." She grimaced. "That kept him conscious for a while. Take a look." A nod at Pulaski.

The officer plugged the flash cards into a nearby computer and created files for the case. A moment later photos popped up on the high-def monitors nearby. After years and years in the crime scene business, Rhyme was largely inured to even the most horrific images; these, though, troubled him. The young victim's body had been riddled by the dots of metal. There was little blood, thanks to the searing heat of the projectiles. Had the perp known that's what his weapon would do, sealing the punctures? Keeping his victims conscious to feel the pain? Was this part of his MO? Rhyme could understand now why Sachs was so troubled.

"Christ," the big detective muttered.

Rhyme shook aside the image and asked, "Who was he?"

"Name was Luis Martin. Assistant manager in a music store. Twenty-eight. No record."

"No connection to Algonquin, MTA… any reason anybody'd want him dead?"

"None," Sachs said.

"Wrong time, wrong place," Sellitto summarized.

Rhyme said, "Ron. The coffee shop? What'd you find?"

"A man in dark blue overalls came into the place about ten forty-five. He had a laptop with him. He went online."

"Blue overalls?" Sellitto asked. "Any logo? ID?"

"Nobody saw. But the Algonquin workers there, their uniforms were the same dark blue."

"Get a description?" the rumpled cop persisted.

"Probably white, probably forties, glasses, dark cap. Couple people said no glasses and no cap. Blond hair, red hair, dark hair."

"Witnesses," Rhyme muttered disparagingly. You could have a shooter naked to the waist kill somebody in front of ten witnesses and each one would describe him as wearing ten different colored T-shirts. In the past few years his doubt about the value of eyewitnesses had tempered somewhat-because of Sachs's skill in interviewing and because of Kathryn Dance, who'd proved that analyzing body language was scientific enough in most cases to produce repeatable results. Still, he could never completely shake his skepticism.

"And what happened to this guy in the overalls?" Rhyme asked.

"Nobody's really sure. It was pretty chaotic. All they knew was that they heard this huge bang, the whole street went white with the flash and then everybody ran outside. Nobody could remember seeing him after that."

"He took his coffee with him?" Rhyme asked. He loved beverage containers. They were like ID cards, with the DNA and fingerprint information they contained, along with trace that adhered because of the sticky nature of milk, sugar and other additives.

"Afraid he did," Pulaski confirmed.

"Shit. What'd you find at the table?"

"This." Pulaski pulled a plastic envelope out of a milk crate.

"It's empty." Sellitto squinted and teased his imposing belly, maybe scratching an itch, maybe absently dismayed that his latest fad diet wasn't working.

But Rhyme looked at the plastic bag and smiled. "Good job, Rookie."

"Good job?" the lieutenant muttered. "There's nothing there."

"My favorite sort of evidence, Lon. The bits that're invisible. We'll get to that in a minute. I'm wondering about hackers," Rhyme mused. "Pulaski, what about wireless at the coffee shop? I was thinking about it and I'm betting they didn't have it."

"You're right. How'd you know?"

"He couldn't take the chance that it'd be down. He's probably logging in through some cell phone connection. But we need to find out how he got into the Algonquin system. Lon, get Computer Crimes on board. They need to contact somebody in Internet security at Algonquin. See if Rodney's available."

The NYPD Computer Crimes Unit was an elite group of about thirty detectives and support staff. Rhyme worked with one of them occasionally, Detective Rodney Szarnek. Rhyme thought of him as a young man, but in fact he had no idea of his age since he had the boyish attitude, sloppy dress and tousled hair of a hacker-an image and avocation that tend to take years off people.

Sellitto placed the call and after a brief conversation hung up, reporting that Szarnek would call Algonquin's IT team immediately to see about hacking into the grid servers.

Cooper was looking reverently at the wire. "So that's it?" Then lifting another of the bags that contained misshapen metal disks, the shrapnel, he added, "Lucky nobody was walking by. If this'd happened on Fifth Avenue, there could be two dozen people dead."

Ignoring the tech's unnecessary observation, Rhyme focused on Sachs. He saw that her eyes had gone still as she looked at the tiny disks.

In a voice perhaps harsher than necessary, to shake her attention away from the shrapnel, he called, "Come on, people. Let's get to work."

EASING INTO THE booth, Fred Dellray found himself looking at a pale skinny man who could have been a wasted thirty or a preserved fifty.

The guy was wearing a sports jacket that was too big, its source either a very low-end thrift shop or a coat rack, when nobody was looking.

"Jeep."

"Uhm, that's not my name anymore."

"Not your name? Like nacho cheese. Then whose cheese is it?"

"I don't get-"

"Whatcha name now?" Dellray asked, frowning deeply, playing a particular role, one he generally slipped into with people like this. Jeep, or Not Jeep, had been a sadistic junkie the FBI agent had collared in an undercover set that required Dellray to laugh his way through the man's graphic depiction of torturing a college kid who'd reneged on a drug payment. Then came the bust and, after some negotiation and time served, the man became one of Dellray's pets.

Which meant a tight leash that had to be jerked occasionally.

"It was Jeep. But I decided to change it. I'm Jim now, Fred."

Changes. The magic word of the day.

"Oh, oh, speakin' of names: 'Fred… Fred'? I'm your buddy, I'm your best friend? I didn't remember those introductions, signing your dance card, meetin' the parents."

"Sorry, sir."