But then Dennis Baker made a mistake. He got lazy. It wasn't easy finding the right marks for the scam and he decided to go back to some of the earlier targets for a second installment of extortion money.

Some paid the second time. But two of them-Sarkowski and Creeley-were businessmen with pretty tough hides, and while they were willing to pay once to get Baker out of their hair, they drew the line at a second payment. One threatened to go to the police, and one to the press. In early November Baker and a cop from the 118th had kidnapped Sarkowski and driven him to an industrial section of Queens, near where a client of his company had a factory. He'd been shot, the crime staged to look like a mugging. Several weeks later Baker and the same cop had broken into Creeley's high-rise, strung a rope around the businessman's neck and tossed him off the balcony.

They'd stolen or destroyed the men's personal files, books and diaries-anything that might've led back to Baker and his scam. As for the police reports, there was virtually nothing in Creeley's that was incriminating but the Sarkowski file contained references to evidence that a sharp investigator might draw some troubling conclusions from. So one of the people involved in the plan had engineered its disappearance.

Baker thought the deaths would go unnoticed and they continued with their scam-until a young policewoman showed up. Detective Third-Grade Amelia Sachs didn't believe that Benjamin Creeley had committed suicide and started looking into the death.

There was no stopping the woman. They had no choice but to kill her. With Sachs dead or incapacitated Baker doubted that anyone else would follow up on the cases as fervently as she was. The problem, of course, was that if she wereto die, Lincoln Rhyme would deduce immediately that her death was related to the St. James investigation and then nothingwould stop him and Sellitto from pursuing the killers.

So Baker needed Sachs to die for a reason unrelated to the 118th Precinct crimes.

Baker put some feelers out to a few organized crime wise guys he knew and soon he heard from Gerald Duncan, a professional killer who could manipulate crime scenes and set up fake motives to steer suspicion completely away from the man or woman hiring him to kill. "Motive is the one sure way to get yourself caught," Duncan had explained. "Eliminate the motive, you eliminate suspicion."

They'd agreed on a price-brother, the man wasn't cheap-and Duncan had gone to work planning the job.

Duncan tracked down some loser he could use to feed information about the Watchmaker to the police. Vincent Reynolds turned out to be a perfect patsy, soaking up the story Duncan fed him-about going psycho because of a dead wife and killing apathetic citizens.

Then, the previous day, Duncan had put the plan into operation. The Watchmaker killed the first two of the victims, picked at random-some guy he'd kidnapped from West Street in the Village and murdered on the pier and the one in the alley a few hours later. Baker had made sure Sachs was assigned to the case. There were two more attempted murders by the killer-the fact they didn't succeed was irrelevant; the Watchmaker was still one spooky doer, who needed to be stopped fast.

Then Duncan made his next moves: sending Vincent to attack Kathryn Dance, so that the police would believe that the Watchmaker was willing to kill police officers, and setting up Vincent to be captured and dime the Watchmaker out to the police.

It was now time for the final step: The Watchmaker would kill yet another cop, Amelia Sachs, her death entirely the work of a vengeful killer, unrelated to the 118th Precinct investigation.

Duncan now asked, "She found out you were spying on her?"

Baker nodded. "You called that right. She's one smart bitch. But I did what you suggested."

Duncan anticipated that she'd be suspicious of everyone except people she knew personally. He'd explained that when people suspect you, you have to give them another-harmless-reason for your behavior. You simply confess to the lesser crime, act contrite and they're satisfied; you're off the suspect list.

At Duncan's suggestion, Baker asked some officers about Sachs. He heard rumors that she'd been involved with a crooked cop and he'd ginned up an email from someone in the Big Building and used that as a reason to be spying on her. She wasn't happy, but she didn't suspect him of anything worse.

"Here's the plan," Duncan now explained, showing him a diagram of an office building in Midtown. "This's where the last victim works. Her name's Sarah Stanton. She's got a cubicle on the second floor. I picked the place because of the layout. It'll be perfect. I couldn't put one of the clocks there because the police announced the killer was using them-but I pulled up the time and date window on her computer."

"Good touch."

Duncan smiled. "I thought so." The killer's voice was soft, his words precise, but the tone was filled with the modest pleasure of an artisan showing off a finished piece of furniture or a musical instrument…or a watch, Baker reflected.

Duncan explained that he'd dressed like a workman, waited until Sarah went out then planted a fire extinguisher, filled with flammable alcohol. In a few minutes Baker was to call Rhyme or Sellitto and report that he'd found evidence of where the extinguisher bomb was planted. The ESU and bomb squad would then speed to the office, Amelia Sachs too.

"I set the device up so that if she moves the extinguisher a certain way, it'll spray her with alcohol and ignite. Alcohol burns really fast. It'll kill or injure her but won't set fire to the whole office." The police, he continued, might even disarm the device and save the woman. It wouldn't matter; all that Duncan cared about was getting Amelia Sachs into the office to search the scene.

Sarah's cubicle was at the end of a narrow corridor. Sachs would be searching it alone, as she always did. When she turned her back, Baker, waiting nearby, would shoot her and anybody else present. The weapon he'd use was Duncan's.32 automatic, loaded with bullets from the same box he'd intentionally left in the SUV for the police to find. After shooting Sachs, Baker would break a nearby window, which was fifteen feet above an alleyway. He'd throw the gun out, making it seem as if the Watchmaker had leapt out the window and escaped, dropping the gun. The unusual murder weapon, linked to the rounds found in the Explorer, would leave no doubt that the Watchmaker was the killer.

Sachs would be dead and the investigation into the corruption at the 118th Precinct would grind to a halt.

Duncan said, "Let some other officers get to her body first but it'd be a nice touch if you pushed them aside and tried to resuscitate her."

Baker said, "You think of everything, don't you?"

"What's so miraculous about timepieces," Duncan said, gazing at the moon-faced clock, "is that none of them ever has more or fewer parts than is needed to do what the watchmaker intends. Nothing missing, but nothing superfluous." He added in a soft voice, "It's pure perfection, wouldn't you say?"

Amelia Sachs and Ron Pulaski were slogging through the cold streets of lower Manhattan, and she was reflecting that sometimes the biggest hurdles in a case weren't from the perps but from bystanders, witnesses and victims.

They were following up on one of the clues that had been uncovered in the church, receipts from a parking garage not far from the pier where the first victim had died. But the attendant was unhelpful. Lady, no, he no familiar. Nobody look like him I remember. Ahmed-maybe he saw him… Oh, but he not here today. No, I don't know his phone number…

And so it went.

Frustrated, Sachs nodded toward a restaurant adjacent to the parking garage. She said, "Maybe he stopped in there. Let's give it a try."