athryn Dance was alone with Rhyme in his town house. Well, Jackson, the Havanese, was present too. Dance was holding the dog.

"That was wonderful," she told Thom. The three of them had just finished a dinner of the aide's beef bourguignon, rice, salad and a Caymus Cabernet. "I'd ask for the recipe but I'd never do it justice."

"Ah, an appreciative audience," he said, glancing at Rhyme.

"I'm appreciative. Just not excessively."

Thom nodded at the bowl that had held the main course. "To him it's 'stew.' He doesn't even try the French. Tell her what you think of food, Lincoln."

The criminalist shrugged. "I'm not fussy about what I eat. That's all."

"He calls it 'fuel,'" the aide said and carted the dishes to the kitchen.

"You have dogs at home?" Rhyme asked Dance, nodding at Jackson.

"Two. They're a lot bigger than this guy. The kids and I take 'em to the beach a couple times a week. They chase seagulls and we chase them. Exercise all around. And if that sounds too healthy, don't worry. Afterward we go for waffles at First Watch in Monterey and replace any calories we've lost."

Rhyme glanced into the kitchen, where Thom was washing dishes and pans. He lowered his voice and asked if she'd engage in bit of subterfuge.

She frowned.

"I wouldn't mind if a bit of that" — he nodded toward a bottle of old Glenmorangie scotch — "ended up in there." The nod shifted toward his tumbler. "You might want to keep it quiet, though."

"Thom?"

A nod. "He enacts Prohibition from time to time. It's rather irritating."

Kathryn Dance knew the value of indulging. (Okay, maybe she'd gained six pounds in Tijuana; that had been a long, long week.) She set the dog down and poured him a good healthy dose. She fit the cup into the holder of his wheelchair, arranging the straw near his mouth.

"Thanks." He took a long sip. "Whatever you're billing the city for your time, I'll authorize double pay. And help yourself. Thom won't give you any grief."

"Maybe some caffeine." She poured a black coffee and allowed herself one of the oatmeal cookies that the aide had set out. He'd baked them himself.

Dance glanced at her watch. Three hours earlier in California. "Excuse me for a minute. Check in at home."

"Go right ahead."

She made a call on her mobile. Maggie answered.

"Hey, sweets."

"Mommy."

The girl was a talker and Dance got a ten-minute account of a Christmas shopping trip with her nana. Maggie concluded with: "And then we came back here and I read Harry Potter."

"The new one?"

"Uh-huh."

"How many times is that?"

"Six."

"Wouldn't you like to read something different? Expand your horizons?"

Maggie replied, "Gee, Mom, like, how many times've you listened to Bob Dylan? That Blonde on Blonde album. Or U2?"

Unassailable logic. "You got me there, sweets, only don't say like."

"Mom. When're you coming home?"

"Tomorrow probably. Love you. Put your brother on."

Wes came on the phone and they too chatted for a while, the conversation more halting and more serious in tone. He'd been dropping hints about taking karate lessons and now he asked her point-blank if he could. Dance, though, preferred he take up something less combative if he wanted a sport other than soccer and baseball. His muscular body would be perfect for tennis or gymnastics, she thought, but those didn't have much appeal to him.

As an interrogator, Kathryn Dance knew a great deal about the subject of anger; she saw it in the suspects as well as the victims she interviewed following crimes. She believed that Wes's recent interest in martial arts came from the occasional anger that settled like a cloud over him after his father's death. Competition was fine but she didn't think it would be healthy for him to engage in a fighting sport, not at this point in his life. Sanctioned fury can be a very dangerous thing, especially with youngsters.

She talked to him about the decision for some time.

Working on the Watchmaker case with Rhyme and Sachs had made Kathryn Dance very aware of time. She realized how much she used it in her work — and with her children. The passage of time, for instance, diffuses anger quickly (outbursts can rarely be sustained longer than three minutes) and weakens resistance to opposing positions — better than strident argument in most cases. Dance didn't now say no to karate but got him to agree to try a few tennis lessons. (She'd once overheard him say to a friend, "Yeah, it sucks when your mom's a cop." Dance had laughed hard to herself at that.)

Then his mood changed abruptly and he was talking happily about a movie he'd seen on HBO. Then his phone was beeping with a text message from a friend. He had to go, bye, Mom, love you, see you soon.

Click.

The millisecond of spontaneous "love you" made the whole negotiation worth it.

She hung up and glanced at Rhyme. "Kids?"

"Me? No. I don't know that they'd be my strong suit."

"They're nobody's strong suit until you have them."

He was looking at her ubiquitous iPod earphones, which dangled around her neck like a stethoscope on a doctor. "You like music, I gather... How's that for a clever deduction?"

Dance said, "It's my hobby."

"Really? You play?"

"I sing some. I used to be a folkie. But now, if I take time off, I throw the kids and the dogs into the back of a camper and go track down songs."

Rhyme frowned. "I've heard of that. It's called —"

"Song catching is the popular phrase."

"Sure. That's it."

This was a passion for Kathryn Dance. She was part of a long tradition of folklorists, people who would travel to out-of-the-way places to field-record traditional music. Alan Lomax was perhaps the most famous of these, hiking throughout the U.S. and Europe to capture old-time songs. Dance went to the East Coast from time to time but those tunes had been well documented, so most of her recent trips were to inner cities, Nova Scotia, Western Canada, the bayou and places with large Latino populations, like Southern and Central California. She'd record and catalog the songs.

She told this to Rhyme and explained too about a website she and a friend maintained with information on the musicians, the songs and the music itself. They helped the musicians copyright their original songs and distributed to them any fees listeners paid for downloads of the music. Several musicians had been contacted by record companies, which had bought their music for sound tracks of independent films.

Kathryn Dance didn't tell Rhyme, though, that there was more to her relationship with music.

Dance often found herself overloaded. To do her job well, she needed to hard-wire herself to the witnesses and criminals she interviewed. Sitting three feet from a psychotic killer, jousting with him for hours or days or weeks, was an exhilarating process, but exhausting and debilitating too. Dance was so empathic and so closely connected to her subjects that she felt their emotions long after the sessions ended. She heard their voices in her mind, endlessly looping through her thoughts.

Sí­, sí­, okay, sí­, I kill her. I cut her throat... Well, her son too, that boy. He there. He see me. I have to kill him, I mean, who wouldn't? But she deserve it, the way she look at me. It no my fault. Can I have that cigarette you talking about?

The music was a miracle cure. If Kathryn Dance was listening to Sonny Terry and Brownie McGhee or U2 or Dylan or David Byrne, she wasn't replaying the memory of an indignant Carlos Allende complaining that the victim's engagement ring cut his palm while he was slitting her throat.

It hurt, what I'm saying. Bad. That bitch...

Lincoln Rhyme asked, "You ever perform professionally?"

She had, some. But those years, in Boston and then Berkeley and North Beach in San Francisco, had left her empty. Performance seems personal but she'd found that it's really about you and the music, not you and the listener. Kathryn Dance was much more curious about what other people had to say — and to sing — about themselves, about life and love. She realized that with music, as with her job, she preferred the role of professional audience.

She told Rhyme, "Tried it. But in the end I just thought it was better to keep music as a friend."

"So you became a cop instead. About a hundred-and-eighty-degree change."

"Go figure."

"How'd that happen?"

Dance debated. Normally reluctant to talk about herself (listen first, talk last), she nonetheless felt a connection to Rhyme. They were rivals, in a way — forensics versus kinesics — yet ones who shared a common purpose. Also, his drive and his stubbornness reminded her of herself. His clear love of the hunt, as well.

So she said, "Jonny Ray Hanson... Jonny without an h."

"A perp?"

She nodded and told him the story. Six years ago Dance had been hired by prosecutors as a consultant to help pick jurors in the case of the State of California v. Hanson.

A thirty-five-year-old insurance agent, Hanson lived in Contra Costa County, north of Oakland, a half hour from the home of his ex-wife, who had a restraining order against him. One night someone had tried to break into her house. The woman wasn't home and some county sheriff's deputies, who regularly patrolled past her house, spotted and chased him, though the perp got away.

"Doesn't seem all that serious... but there was more to it. The sheriff's department was concerned because Hanson kept up the threats and had assaulted her twice. So they picked him up and talked to him for a while. He denied it and they let him go. But finally they thought they could make a case and arrested him."

Because of the prior offenses, Dance explained, a B-and-E charge would put him away for at least five years — and give his ex-wife and college-age daughter a respite from his harassment.

"I spent some time with them at the prosecutor's office. I felt so bad for them. They'd been living in absolute terror. Hanson would mail them blank sheets of paper, he'd leave weird messages on their phone. He'd stand exactly one block away — that was okay under the restraining order — and stare at them. He'd have food delivered to their house. Nothing illegal but the message was clear: I'll always be watching you."

To go shopping, mother and daughter had been forced to sneak out of their neighborhood in disguise and go to malls ten or fifteen miles from where they lived.

Dance had picked what she thought was a good jury, stacking it with single women and professional men (liberal but not too liberal), who'd be sympathetic to the victims' situation. As she often did, Dance stayed through trial to give the prosecution team advice — and to critique her choices, as well.

"I watched Hanson in court carefully and I was convinced he was guilty."

"But something went wrong?"

Dance nodded. "Witnesses couldn't be located or their testimony fell apart, physical evidence either disappeared or was contaminated, Hanson had a series of alibis that the prosecution couldn't shake: Every key point in the DA's case was countered by the defense; it was as if they'd bugged the prosecutor's office. He was acquitted."

"That's tough." Rhyme looked her over. "But there's more to the story, I sense."

"I'm afraid there is. Two days after the trial, Hanson tracked down his wife and daughter in a shopping center parking garage and knifed them to death. The daughter's boyfriend was with them. Hanson killed him too. He fled the area and was finally caught — a year later."

Dance sipped her coffee. "After the murders, the prosecutor was trying to figure out what went wrong at trial. He asked me to look over the transcript of the initial interview at the sheriff's office." She gave a bitter laugh. "When I reviewed it I was floored. Hanson was brilliant — and the sheriff's department deputy who interviewed him was either totally inexperienced or lazy. Hanson played him like a fish. He ended up learning enough about the prosecution's case to completely undermine it — which witnesses to intimidate, what evidence he should dispose of, what kind of alibis he should come up with."

"And I'm assuming he got one other bit of information," Rhyme said, shaking his head.

"Oh, yes. The deputy asked if he'd ever been to Mill Valley. And later he asked if he ever frequented shopping centers in Marin County. That gave Hanson enough information to know where his ex and their daughter sometimes shopped. He basically just camped out around the Mill Valley mall until they showed up. That's where he killed them — and they didn't have any police protection there since it was a different county.

"That night I drove back home along Route One — the Pacific Coast Highway — instead of taking the One Oh One, the big freeway. I was thinking, Here I am being paid a hundred and fifty bucks an hour to anybody who needs a jury consultant. That's all fine, nothing immoral about that — it's the way the system works. But I couldn't help but think that if I'd conducted that interview myself, Hanson would've gone to jail and three people wouldn't have died.

"Two days later I signed up for the academy, and the rest, as they say, is history. Now, what's the scoop with you?"

"How'd I decide to become a cop?" He shrugged. "Nothing quite so dramatic. Boring, actually... just kind of fell into it."

"Really?"

Rhyme laughed.

Dance frowned.

"You don't believe me."

"Sorry, was I studying you? I try not to. My daughter says I look at her like she's a lab rat sometimes."

Rhyme sipped more scotch and said with a coy smile, "So?"

She lifted an eyebrow. "So?"

"I'm a tough nut for a kinesics expert, somebody like me. You can't really read me, can you?"

She laughed. "Oh, I can read you just fine. Body language seeks its own level. You give just as much away with your face and eyes and head as somebody who's got the use of his whole body."

"Really?"

"That's the way it works. It's actually easier — the messages are more concentrated."

"I'm an open book, hm?"

"Nobody's an open book. But some books are easier to read than others."

"I remember you were talking about the response states when you interrogate somebody. Anger, depression, denial, bargaining... After the accident I had plenty of therapy. Didn't want to, but when you're flat on your back, what can you do? The shrinks told me about the stages of grief. They're pretty much the same."

Kathryn Dance knew the stages of grief very well. But, once again, this was not a subject for today. "Fascinating how the mind deals with adversity — whether it's physical trauma or emotional stress."

Rhyme looked off. "I fight with the anger a lot."

Dance kept her deep green eyes on Rhyme and shook her head. "Oh, you're not nearly as angry as you make out you are."

"I'm a crip," he said stridently. "Of course I'm angry."

"And I'm a woman cop. So we both have a right to get pissed off sometimes. And depressed for all sorts of reasons and we deny things. But anger? No, not you. You've moved on. You're in acceptance."

"When I'm not tracking down killers" — a nod at the evidence board — "I'm doing physical therapy. A lot more than I ought to be doing, Thom tells me. Ad nauseam, by the way. That's hardly accepting things."

"That's not what acceptance is. You accept the condition and you fight back. You're not sitting around all day. Oh, sorry, I guess you are."

The sorry was not an apology. Rhyme couldn't help but laugh hard and Dance saw that she scored big points with the joke. She'd assessed that Rhyme was a man with no respect for delicacy and political correctness.

"You accept reality. You're trying to change it but you're not lying to yourself. It's a challenge, it's tough, but it doesn't anger you."

"I think you're wrong."

"Ah, you just blinked twice. Kinesic stress response. You don't believe what you're saying."

"You're a tough woman to argue with." He drained the glass.

"Ah, Lincoln, I've got your baseline down. You can't fool me. But don't worry. Your secret's safe."

The front door opened. Amelia Sachs walked into the room. She tossed off her jacket and the women greeted each other. It was obvious from her posture and her eyes that something was troubling her. She went to the front window and looked out, then pulled the shade down.

"What's the matter?" Rhyme asked.

"I just got a call from a neighbor. She said that somebody was at my building today, asking about me. He gave the name Joey Treffano. I used to work with Joey in Patrol. He wanted to know what I was up to, asked a lot of questions, looked over the building. My neighbor thought it seemed funny and gave me a call."

"And you think somebody was pretending to be Joey? It wasn't him?"

"Positive. He left the force last year and moved to Montana."

"Maybe he came back to visit, wanted to look you up."

"If he did, it was his ghost. He was killed in a motorcycle accident last spring... And both Ron and I've been tailed. And earlier today somebody went through my purse. It was in my car, locked up. They broke in."

"Where?"

"At the scene on Spring Street, near the florist's shop."

It was then that something in the back of Kathryn Dance's mind began to nag. She finally seized the memory. "There's one thing I ought to say... Might be nothing but it's worth mentioning."

The hour was late but Rhyme had called everyone together. Sellitto, Cooper, Pulaski and Baker.

Amelia Sachs was now looking them over.

She said, "We have a problem I want you to know about. Somebody's been tailing me and Ron. And Kathryn just told me that she thought she'd seen someone too."

The kinesics expert nodded.

Sachs then glanced at Pulaski. "You told me you thought you'd seen that Mercedes. Have you seen it again?"

"Nope. Not since this afternoon."

"How about you, Mel? Anything unusual?"

"I don't think so." The slim man pushed his glasses higher on his nose. "But I never pay attention. Lab techs aren't used to being tailed."

Sellitto said he thought he might've seen someone but wasn't sure.

"When you were in Brooklyn today, Dennis," Sachs asked Baker, "you get the feeling that somebody was watching you?"

He paused. "Me? I wasn't in Brooklyn."

She frowned. "But... you weren't?"

Baker shook his head. "No."

Sachs turned to Dance, who'd been studying Baker. The California agent nodded.

Sachs's hand strayed to her Glock and she turned toward Baker. "Dennis, keep your hands where we can see them."

His eyes went wide. "What?"

"We need to have a little talk."

None of the others in the room — who'd been briefed beforehand — gave any reaction, though Pulaski kept his hand near his own piece. Lon Sellitto stepped behind Baker.

"Hey, hey, hey," the man said, frowning and looking over his shoulder at the heavyset detective. "What is this?"

Rhyme said, "We want to ask you a few questions, Dennis."

What Kathryn Dance had felt worth mentioning was something very subtle and it wasn't that somebody'd been following her; Sachs had simply said that to keep Dennis Baker at ease. Dance recalled that earlier, when Baker had mentioned that he'd been at the scene in front of the florist's workshop, she'd observed him crossing his legs, avoiding eye contact and sitting in a position that suggested possible deception. His exact comment at that moment was that he'd just left the scene and couldn't recall if Spring Street had been reopened or not. Since he'd have no reason to lie about where he was, she didn't think anything of it at the time.

But when Sachs mentioned that somebody had broken into her car at the scene — where Baker had been — she remembered the lieutenant's possibly deceptive behavior. Sachs had called Nancy Simpson, who'd been at the scene, and asked her what time Baker had left.

"Right after you, Detective," the officer had said.

But Baker had said he'd stayed for almost an hour.

Simpson added that she believed Baker had gone to Brooklyn. Sachs had asked him about being in the borough now to see if Dance could pick up signs of possible deception.

"You broke into my car and went through my purse," she said. Her voice was harsh. "And you asked a neighbor about me — pretending to be a cop I'd worked with."

Would he deny it? This could blow up in their faces if Dance and Sachs were wrong.

But Baker looked down at the floor. "Look, this's all a misunderstanding."

"You talked to my neighbor?" she asked angrily.

"Yes."

She eased closer to him. They were about the same height but Sachs, in her anger, seemed to tower over him. "You drive a black Mercedes?"

He frowned. "On a cop's salary?" This answer seemed genuine.

Rhyme glanced at Cooper, who went to the DMV database. The tech shook his head. "Not his wheels."

Well, they got one wrong. But Baker'd clearly been nabbed at something.

"So, what's the story?" Rhyme asked.

Baker looked at Sachs. "Amelia, I really wanted you on the case. You and Lincoln together, you're an A team. And frankly, you guys get good press. And I wanted to be associated with you. But after I convinced the top floor to bring you on board, I heard there was a problem."

"What?" she asked firmly.

"In my briefcase, there's a sheet of paper." He nodded to Pulaski, who was standing beside the battered attaché case. "It's folded up. In the top right-hand side."

The rookie opened the case and found it.

"It's an email," Baker continued.

Sachs took it from Pulaski. She read it once, frowning. She was motionless for a moment. Then she stepped closer to Rhyme and set it on the wide arm of his wheelchair. He read the brief, confidential note. It was from a senior inspector at Police Plaza. It said that a few years earlier Sachs had been involved with an NYPD detective, Nicholas Carelli, who'd been convicted of various charges, including hijackings, bribes and assault.

Sachs had not been implicated in the incidents but Carelli had been released not long ago and the brass were concerned that she might have had some contact with him. They didn't think she'd done anything illegal but if she was seen with him now, it could be, the email said, "embarrassing."

Sachs cleared her throat and said nothing. Rhyme had known all about Nick and Sachs — how they'd talked about getting married, how close they'd been, how shattered she'd been by his secret life as a criminal.

Baker shook his head. "I'm sorry. I didn't know how else to handle it. I was told to give them a complete report. Details of where I'd observed you, things I learned about you. On the job and off. Any connection with this Carelli or any of his friends."

"That's why you were pumping me for information about her," Rhyme said angrily. "This's bullshit."

"All respect, Lincoln, I'm putting myself on the line here. They wanted to pull her anyway. They didn't want her on a high-profile case, not with that history. But I said no."

"I haven't seen Nick in years. I didn't even know he was out."

"And that's what I'm going to tell them." He nodded toward his briefcase again. "My notes're in there." Pulaski found some more sheets of paper. He gave them to Sachs and she read through then laid them out for Rhyme to read. They were jottings about the times he'd observed her and questions he'd asked, what he'd seen in her calendar and address book, what people had said about her.

"You broke and entered," Sellitto said.

"Conceded. Over the line. Sorry."

"Why the fuck didn't you come to me?" Rhyme snapped.

"Or any of us," Sellitto said.

"This came from high up. I was told to keep it quiet." Baker turned to Sachs. "You're upset. I'm sorry about that. But I really wanted you on the case. It was the only way I could think of. I've already told them my conclusions. The whole thing's gone away. Look, please, can we put this behind us and get on with our job?"

Rhyme glanced at Sachs, and what hurt him the most was to see her reaction to the incident: She wasn't angry any longer. She seemed embarrassed to have been the cause of this controversy and trouble to her fellow officers, distracting them from their mission. It was so unusual — and therefore so hard — to see Amelia Sachs pained and vulnerable.

She handed the email back to Baker. Without a word to anyone she grabbed her jacket and walked calmly out the doorway, pulling her car keys from her pocket.