Finally Haumann told them that all of his officers had finished the sweep; the Watchmaker had escaped.

"Hell," Dennis Baker muttered. "We were so close."

Discouraged, Rhyme said, "Well, walk the grid and tell me what you find."

They signed off. Haumann sent two teams to stake out the warehouse that Duncan had used as a staging site in case the killer returned there and Sachs dressed in the white Tyvek bodysuit and grabbed a metal suitcase containing basic evidence collection and preservation equipment.

"I'll help," Pulaski said, also dressing in the white overalls.

She handed him the suitcase and she picked up another one.

On the second floor, she paused and surveyed the hallway. After photographing it Sachs entered Lanam Flooring and proceeded to Sarah Stanton's workstation.

She and Pulaski set up the suitcases and extracted the basic evidence collection equipment: bags, tubes, swabs, adhesive rollers for trace, electrostatic footprint sheets and latent-print chemicals and equipment.

"What can I do?" Pulaski asked. "You want me to search the stairwells?"

She debated. They'd have to be searched eventually but she decided that it would be better to run them herself; they were the most logical entry and exit routes for the Watchmaker and she wanted to make certain that no evidence was missed. Sachs surveyed the layout of Sarah's cubicle and then noticed an empty workstation next to it. It was possible that the Watchmaker had waited there until he had a chance to plant the bomb. Sachs told the rookie, "Run that cubicle."

"You got it." He stepped into the cubicle, pulled out his flashlight and began walking a perfect grid. She caught him sniffing the air too, another of Lincoln Rhyme's dictates for crime scene officers searching. This boy was going to go places, she reflected.

Sachs stepped into the cubicle where they'd found the device. She heard a noise and glanced back. It was only Dennis Baker. He came up the corridor and stopped about twenty feet from the cubicles, far enough away so there was no risk of contaminating the scene.

She wasn't sure exactly why he was here but, since they still weren't sure where the Watchmaker was, she was grateful for his presence.

Search well but watch your back…

This was the difference:

Detective Dennis Baker-along with a cop from the 118th-had murdered Benjamin Creeley and Frank Sarkowski. It had been tough but they'd done it without hesitation. And he was prepared to kill any other civilians who threatened their extortion scheme. No problem at all. Five million dollars in cash-their haul to date-buries a lot of guilt.

But Baker had never killed a fellow cop.

Frowning, fidgeting, he was watching Amelia Sachs and the kid, Pulaski, who also presented an easy target.

A big difference.

This was killing family members, fellow officers.

But the sad truth was that Sachs and, by association, Pulaski, could destroy his life.

And so there was no debate.

He now studied the scene. Yes, Duncan had it planned perfectly. There was the window. He glanced out. The alley, fifteen feet below, was deserted. And next to him was the gray metal chair the killer had told him about, the one he'd pitch through the window after killing the officers. There was the large air-conditioning intake vent, whose grate he'd remove after the shots, to make it appear that the Watchmaker had been hiding inside.

A deep breath.

Okay, it's time. He had to act fast, before anyone else came onto the scene. Amelia Sachs had sent the other officers into the main hallway but someone could return here at any minute.

He took the.32 and quietly pulled back the slide to make certain a bullet was in the chamber. Holding the gun behind his back, he eased closer. He was staring at Sachs, who moved around the crime scene almost like a dancer. Precise, fluid, lost in concentration, as she searched. It was beautiful to watch.

Baker tore himself out of this reverie.

Who first? he debated.

Pulaski was ten feet from him, Sachs twenty, both facing away.

Logically, Pulaski should be the first one, being closer. But Baker had learned from Lincoln Rhyme about Sachs's skill as a marksman. She could draw and fire in seconds. The kid had probably never even fired his weapon in combat. He might get his hand on his pistol after Baker killed Sachs, but the rookie would die before he could draw.

A few breaths.

Amelia Sachs unwittingly cooperated. She stood up from where she'd been crouching. Her back presented a perfect target. Baker pointed his gun high on her spine and squeezed the trigger.

To most people the sound would be a simple metallic click, lost in the dozen other ambient noises of a big-city office building.

To Amelia Sachs, though, it was clearly the spring-activated firing pin of an automatic weapon striking the primer cap of a malfunctioning bullet, or someone dry-firing a gun. She'd heard the distinctive sound a hundred times-from her own pistols and her fellow officers'.

This click was followed with what usually came next-the shooter working the slide to eject the bad round and chamber the next one in the clip. In many cases-like now-the maneuver was particularly frantic, the shooter needed to clear the weapon instantly and get a new bullet ready fast. It could be a matter of life and death.

This all registered in a fraction of a second. Sachs dropped the roller she was using to collect trace. Her right hand slammed to her hip-she always knew the exact place where her holster rested-and an instant later she spun around, hunched in a combat shooting position, her Glock in her hand, facing where the sound had come from.

She saw in her periphery, to her right, Ron Pulaski, standing up in the next office, looking at her weapon, alarmed, wondering what she was doing.

Twenty feet away was Dennis Baker, his eyes wide. In his gloved hand was a tiny pistol, a.32, she thought, pointed her way, as he worked the slide. She noted that it was an Autauga MKII, the type of gun that Rhyme speculated the Watchmaker might have.

Baker blinked. Couldn't speak for a moment. "I heard something," he said quickly. "I thought he'd come back, the Watchmaker."

"You pulled the trigger."

"No, I was just chambering a round."

She glanced at the floor, where the bum shell lay. The only reason for it to be there was if he'd tried to shoot, then ejected the defective bullet.

Taking the tiny.32 in his left hand, Baker lowered his right. It strayed to his side. "We have to be careful. I think he's back."

Sachs centered the sights directly on Baker's chest.

"Don't do it, Dennis," she said, nodding toward his hip, where his regulation pistol rested. "I willfire. I'm assuming you've got armor under your suit. My first slug'll be on your chest but two and three'll go higher. It won't be nice."

"I…You don't understand." His eyes were wide, panicked. "You have to believe me."

Wasn't that one of the key phrases that signaled deception, according to Kathryn Dance?

"What's going on?" Pulaski asked.

"Stay there, Ron," Sachs ordered. "Don't pay attention to a thing he says. Draw your weapon."

"Pulaski," Baker said, "she's going nuts. Something's wrong."

But from the corner of her eye she saw the rookie pull his weapon and aim it in Baker's direction.

"Dennis, set the thirty-two on the table. Then with your left hand take your service piece by the grip-thumb and index finger only. Set it down too then move back five steps. Lie facedown. Okay. You clear on that?"

"You don't understand."

She said calmly, "I don't need to understand. I need you to do what I'm telling you."