He tried again. “Command, type, ‘Pam call me period. Lincoln period.’”

And what would he tell her to do if he got through? Sachs had weapons in the place but he didn’t know where she kept them. Pam was an athletic girl, and the intruder didn’t seem much larger than she was. But he’d have a weapon. And, given where he was, he could get a garrote around her neck or a knife into her back before she was even aware of his presence.

And it would happen before his eyes.

Then at last she was swiveling toward the computer. She’d see the message.

Good, keep turning.

Rhyme saw a shadow on the floor across the room. Was the killer moving in closer?

Still talking on her phone, Pam moved toward the computer but she was looking at the keyboard, not the screen.

Look up! Rhyme urged silently.

Please! Read the goddamn message!

But like all kids today, Pam didn’t need to look at the screen to make sure she’d typed correctly. With her cell held tight between cheek and shoulder, she glanced fast at the keyboard as she stabbed the letters with quick strokes.

“gotta go. bye mr Rhyme. C U:-)”

The screen went black.

Amelia Sachs was uncomfortable in the crime-scene Tyvek jumpsuit, with surgeon’s hat and booties. Claustrophobic, nauseous from inhaling the bitter scent of damp paper and blood and sweat in the warehouse.

She hadn’t known Captain Joseph Malloy well. But he was, as Lon Sellitto had announced, “one of ours.” And she was appalled at what 522 had done to him, to extract the information he wanted. She was nearly finished running the scene and carried the evidence-collection bags outside, infinitely grateful for the air here, even though it reeked of diesel fumes.

She kept hearing the voice of her father. As a young girl she’d glanced into her parents’ bedroom and found him in his dress patrolman’s uniform, wiping tears. This had shaken her; she’d never seen him cry. He’d gestured her inside. Hermann Sachs always played straight with his daughter and he’d sat her down on a bedside chair and explained that a friend of his, a fellow officer, had been shot and killed while stopping a robbery.

“Amie, in this business, everybody’s family. You probably spend more time with the guys you work with than you do with your own wife and kids. Every time somebody in blue dies, you die a little bit too. Doesn’t matter, patrol or brass, they’re all family and it’s the same pain when you lose somebody.”

And she now felt the pain he’d been speaking of. Felt it very deeply.

“I’m finished,” she said to the crime-scene crew, who were standing beside their rapid response van. She’d searched the scene alone but the officers from Queens had videotaped and photographed it and walked the grid at the secondary scenes-the likely entrance and exit routes.

Nodding to the tour doctor and her associates from the M.E.’s office, Sachs said, “Okay, you can get him to the morgue.”

The men, in their thick green gloves and jumpsuits, walked inside. Assembling the evidence in the milk crates for transport to Rhyme’s lab, Sachs paused.

Someone was watching her.

She’d heard a tink of metal on metal or concrete or glass from up a deserted alleyway. A fast look, and she believed she saw a figure hiding near a deserted factory’s loading dock, which had collapsed years ago.

Search carefully, but watch your back…

She remembered the scene at the cemetery, the killer, wearing the swiped police hat, watching her. Felt the same uneasiness she had there. She left the evidence bags and walked down the alley, hand on her pistol. She saw no one.

Paranoia.

“Detective?” one of the techs called.

She kept going. Was there a face behind that filthy window?

“Detective,” he persisted.

“I’ll be right there.” A little irritation in her voice.

The crime-scene tech said, “Sorry, it’s a call. From Detective Rhyme.”

She always shut her phone off when she got to a scene to avoid distractions.

“Tell him I’ll call him right back.”

“Detective, he says it’s about somebody named Pam. There’s been an incident at your town house. You’re needed right away.”

Amelia Sachs ran inside fast, oblivious to the pain in her knees.

Past the police at the door, not even nodding to them. “Where?”

One officer pointed toward the living room.

Sachs hurried into the room…and found Pam on the couch. The girl looked up, her face pale.

The policewoman sat beside her. “You’re all right?”

“I’m fine. A little freaked out is all.”

“Nothing hurt? I can hug you?”

Pam laughed and Sachs flung her arms around the girl. “What happened?”

“Somebody broke in. He was here while I was. Mr. Rhyme could see him behind me on the webcam. He kept calling and on the, like, fifth ring or something, I picked up and he told me to start screaming and get out.”

“And you did?”

“Not really. I kind of ran into the kitchen and got a knife. I was pretty pissed. He took off.”

Sachs glanced at a detective from the local Brooklyn precinct, a squat African-American man, who said in a deep baritone, “He was gone when we got here. Neighbors didn’t see anything.”

So it had been her imagination at the warehouse crime scene where Joe Malloy was killed. Or maybe some kid or wino curious about what the cops were doing. After killing Malloy, 522 had come to her place-to look for files or evidence or to finish the job he’d started: kill her.

Sachs walked through the town house with the detective and Pam. The desk had been ransacked but nothing seemed to be missing.

“I thought maybe it was Stuart.” Pam took a breath. “I kind of broke up with him.”

“You did?”

A nod.

“Good for you… But it wasn’t him?”

“No. The guy here was wearing different clothes and wasn’t built like Stuart. And, yeah, he’s a son of a bitch but he’s not going to break into somebody else’s town house.”

“You get a look at him?”

“Naw. He turned and ran before I could see him real clearly.” She’d noticed only his outfit.

The detective explained that Pam had described the burglar as a male, white or light-skinned black or Latino, medium build, wearing blue jeans and a dark blue plaid sports jacket. He’d called Rhyme too, after he’d learned of the webcam, but the criminalist hadn’t seen anything more than a vague form in the hallway.

They found the window through which he’d broken in. Sachs had an alarm system but Pam had shut it off when she’d arrived.

She looked around the place. The anger and dismay she’d felt at Malloy’s horrible death faded, replaced by the same uneasiness, and vulnerability, that she’d been aware of at the cemetery, at the warehouse where Malloy had died, at SSD…in fact, everywhere since they’d started the pursuit of 522. Like at the scene near DeLeon’s house: Was he watching her now?

She saw motion outside the window, a flash of light… Was it from the blowing leaves in front of nearby windows reflecting the pale sunlight?

Or was it 522?

“Amelia?” Pam asked in a soft voice, looking around uneasily herself. “Everything okay?”

This brought Sachs back to reality. Get to work. And fast. The killer had been here-and not that long ago. Goddamnit, find out something useful. “Sure, honey. It’s fine.”

A patrol officer from the precinct asked, “Detective, you want somebody from Crime Scene to look it over?”

“That’s okay,” she said with a glance to Pam and a tight smile. “I’ll handle it.”

Sachs got her portable crime-scene kit from the trunk of her car, and she and Pam searched together.

Well, Sachs did the searching but Pam, standing clear of the perimeter, described exactly where the killer had been. Though her voice was unsteady, the girl was coolly efficient.