"Next best thing. Yardley hung out with me while I recuperated in Athens, and eventually, I moved some of my stuff into a flat she kept in London. You can do the math; it was great fun but it was complicated. She had a job that she couldn't talk about, and I had one that I wouldn't. We shared a place but both traveled." They stopped at a light in Columbus Circle, just a few blocks from the precinct. "I won't lie to you, it was good while it lasted. But it didn't last."

"Conflict of interest?"

"The biggest. I met you." Nikki turned to him, and they stared at each other until a horn honked behind her on the green light. She drove on, and he continued, "That's when I stopped seeing her."

Nikki thought about the intimacy of Yardley's greeting, and her undisguised physicality with Rook, and thought maybe she had a new understanding of Agent Yardley Bell's interest in her case. But the DHS meeting had told her something else more important. If Homeland was pinging Salena Kaye's cell phone calls deep in a Situation Room bunker, something big was definitely going on with Tyler Wynn and his band of conspirators.

Heat double-parked her Crown Vic along with the other police vehicles in front of the precinct on West 82nd. "Wouldn't lock it up," called Ochoa. He and Raley stepped out of the walled parking lot on their way to the Roach Coach. "Got a fresh homicide."

Nikki knew these guys and could read the signs: their impatient eyes, the pace of their strides. Heat's gut told her things were about to get jerked into a new dimension. "What?" was all she said.

"There's string," said Raley.

His partner added, "Looks like we have ourselves a serial killer."

THREE.

Against the dimming of the day, the crime scene floods could have been lights from one of Manhattan's ubiquitous movie shoots. But as Heat and Rook rolled south on Riverside Drive, approaching 72nd, there were no box trucks, no RV dressing rooms, no port-a-potties with doors marked "Lucy" and "Desi." When they pulled up, she parked behind the van from the Office of the Chief Medical Examiner. None of this would be make-believe.

Nikki got out and paused in the street before she closed her door. Rook asked her if everything was OK. Detective Heat nodded. This time she took her private interval for the deceased and felt ready. Raley and Ochoa joined up from the Roach Coach, and the four moved on to work.

The first thing Heat did when she recognized the victim was to call for the ranking scene supervisor. Nikki never broke stride, just told the sergeant to order up crowd control immediately. "Press, paparazzi, gawkers-n.o.body gets near."

"Whoa," said Rook. "It's Maxine Berkowitz."

"None other," said Raley. "Your Channel 3 Doorbuster."

"Gentlemen" was all Heat needed to say. They quieted, stopping in place. She moved forward, using her palm to shield her face from the powerful CSU lights while she made her Beginner's Eyes tour around the victim. The body of the Channel 3 consumer advocate sat upright on a city bench facing the Eleanor Roosevelt statue in the pedestrian entrance to Riverside Park. Maxine Berkowitz wore a nicer-quality, tan, off-the-rack business suit. Her hair, although heavily sprayed, spiked out at the back where it had been disturbed. Her makeup bore smudges around her lower face and mouth. Both hands rested gently in her lap. To the casual pa.s.serby, she could have been any thirtysomething Manhattan professional taking a break to contemplate the memorial to the First Lady of the World. Except this woman had been murdered.

"Asphyxia through strangulation," said Lauren Parry over her clipboard. "That's my prelim, with the usual caveats about letting me run my tests, and yadda, yadda."

Nikki bent forward to examine the p.r.o.nounced bruise line around the victim's neck. "Not manual."

"I'm betting electrical cord. That contusion is sharply defined. And I see no abrasion or strand pattern like with rope." Heat drew closer and got a sick-sweet whiff. "Chloroform?" The ME nodded. Nikki studied the smear of makeup around the victim's nose and mouth and felt a pang of sadness for the reporter, recalling her own abduction a few months before. She rose up and said, "Show me the string."

The CSU technician's camera flashed one last shot. He picked up the six-inch aluminum ruler he had placed beside the string to ill.u.s.trate scale and said, "All yours."

It sat atop the victim's purse at the other end of the park bench. Red string, similar to the one left with Conklin's body, had been tied to an equal length of yellow string, then coiled as one and placed on the purse in a figure-eight loop. The gesture, the care, the quietness of the message-whatever it meant-brought a chill to Nikki. Then Rook moved close by and she felt his warmth against her.

"What do you know," he said. "A lemniscate."

"A what?" asked Ochoa.

"Lemniscate. The word for infinity sign."

Raley weighed in. "I thought infinity sign was the word for infinity sign."

"Ah, except that's two words."

Nikki looked at Roach and shook her head. "Writer." Then, she said to Rook, "Where'd you learn that, interviewing Stephen Hawking?"

Rook shrugged. "The truth? Snapple cap."

They worked the scene for over an hour, interviewing the teenage boy who had discovered the corpse while he was walking his neighbor's pug and had asked the deceased for an autograph. He'd seen n.o.body else around; in fact, the only reason he paid Maxine Berkowitz any attention was that she was the only one there. The canva.s.s of the nearby dog park yielded nothing to go on but did give Dr. Parry time to set up the OCME privacy screens and run a preliminary temperature and lividity field test. She fixed the time of death as noon to 4 P.M. that day.

Forensics called Heat over to the bench. "Found something when we picked up the victim's purse to bag it." With gloved hands, the technician lifted the purse and revealed, underneath it, a small disc. Nikki crouched down beside it for closer examination, to makes sure it was what she thought it was. She frowned and looked up at the tech. "Weird, huh?" he said. "Rollerblade wheel."

Heat tasked her squad to run the usual checks of facing apartment buildings for eyewitnesses-especially anyone who might have registered a Rollerblader-and to scan for security cams. Then she and Rook set out for Channel 3.

WHNY News occupied the bottom two floors of a media complex wedged between Lincoln Center and the West Side Highway. As she waited for security to clear them, Nikki stared across the courtyard at the neighboring studios where her ex-boyfriend, her mother's killer, had worked as a talent booker for a late night talk show. The wave of betrayal washed over her anew and refreshed her anxiety about Tyler Wynn's whereabouts. Heat sealed it off and focused. One murderer at a time, she thought.

The newsroom felt to Heat like her own bull pen, but with higher technology, brighter colors, and better wardrobe. The buzz of preparing for News 3 @ 10 clicked along with the same measured adrenaline rush of working a murder case on deadline. The pressure and excitement ran in the blood, not in the air. Call it controlled chaos.

The news director, George Putnam, a stocky redhead, was still reeling from the shock of his consumer reporter's murder. Heat walked through a vapor trail of Scotch as she and Rook followed him through a maze of desks. Nikki wondered if the whiskey was Putnam's reaction to the death, or how he managed to mount a nightly newscast in Gotham. They settled into his office, like Captain Irons's at the Twentieth, a gla.s.s box that gave him a view of his world. "This is a big blow to our family," he said. He gestured to the newsroom. "We're all working, but it's hard. We're doing it for Max. She was special, that girl."

The little fans in Heat's bulls.h.i.t filter started to whir, but she said, "That's admirable." Rook caught her eye and, in the way only lovers can, vibed that his antennae had also risen.

Putnam described Maxine Berkowitz as the perfect marriage of reporter and beat. She'd come to WHNY from Columbus, Ohio, as weekend anchor, but "she never won the focus groups, so instead of releasing her, I got the notion to recycle her as a consumer watchdog. You know, an in-your-face viewer advocate. Somebody who'd walk through walls and bust down doors." He dabbed an eye and said, "She herself came up with the segment t.i.tle, 'The Doorbuster.' " He went on to describe a team player, beloved by her coworkers.

Not satisfied with the company line George Putnam handed her, Nikki asked to speak with someone who was close to Maxine. The news director hesitated then led her and Rook onto the set, where News 3's hip-hop meteorologist bent over his weather desk. "Oh my G.o.d," said Rook, "I can't believe I'm actually meeting Coolio Nimbus."

The young black man straightened up quickly, and short dreads danced on his head. But the signature smile and mischievous eyes of New York's Most Playful Weathercaster were dimmed by sadness. This man looked like he had lost his best friend.

Nimbus walked them to his cubicle just off the set. When Nikki got there she turned, looking for Rook, but she had lost him along the way. Heat spotted him gawping at his own face with bewildered fascination as it filled a fifty-four-inch LED monitor above the sports desk. By the time he joined her, she had gotten pretty much the same view of Coolio's best friend Max as she'd gotten from the news director, although the weatherman said, "There's some s.h.i.t maybe you need to know. But I'm not sure I should spill."

"I know this is tough, Mr. Nimbus," said Nikki, "but we need to hear about any possibility if we're going to find your friend's murderer."

A familiar voice interrupted. "Good lord, it's Nikki Heat."

Greer Baxter, the iconic face of WHNY News, towered over them. The veteran news anchor's stiff helmet of blond hair framed her handsome features. The newscaster had several tissues tucked into her blouse collar to keep her neck makeup from rubbing off. Both Heat and Rook rose, but he might as well have been invisible. She clasped Nikki's hand in both of hers and said, "Poor Maxine. Such a tragedy. Such a loss." And then, in a gear shift as smooth as turning the page on the night's top stories, she said, "Now, Nikki Heat, you and I need to have a talk. We need to book your appearance on my little spot."

The spot Greer Baxter humbly referred to, "Greer and Now," was the expanded interview segment that closed out each night's primetime newscast. Baxter had a reputation as a skilled interviewer who scored newsworthy guests. "With all due respect," began Nikki, "I-"

"Ah-ah," said Greer. "I won't take no. We lost one of our own. If you don't have enough information to go on with me tonight, I understand. But I need you. I'm serious. Call me. Or I'll be calling you, Nikki Heat."

After she moved on, Heat turned her attention back to Coolio Nimbus. "What should I know about Maxine Berkowitz?"

Minutes later, back in the news director's office, George Putnam came around his desk and closed his door. "Coolio told you this?" Heat nodded. He flopped into his executive swivel and rocked back with an exhale, deep in painful thought. Then he came forward, resting rolled-up shirtsleeves on his desk and presenting his block of a freckled face to them. "It's true. Max and I had an affair. It started years ago when I began coaching her for her new role."

"As your mistress?" asked Rook.

"As the best d.a.m.ned consumer advocate in TV," he said. "I had this notion that people could sleep together and still work together." Both Heat and Rook kept eyes front. "I was wrong. I knew too much. Running this newsroom, I had to keep secrets from her. She'd find out, of course, when I'd send a memo to the staff about a change, and she'd get all bent about not being told first. It ate us up." Nikki let the silence do the work. Putnam filled it. "I broke it off a year ago. It ended ugly. But that affair was ancient history. I mean, when a romance is over, it's over. Right?"

Rook turned immediately to Nikki and said, "Yes... Absolutely."

Heat said, "Mr. Putnam, I'd like your whereabouts midday today, please." But even as Heat jotted down his statement, she knew it wasn't him and that getting Putnam's alibi was just a formality.

The real killer was somewhere out there.

Rook made their dinner that night in his loft while they drank unfiltered hefeweizen and Nikki watched across the kitchen counter after her bath. "What magic's happening in that oven of yours, Mr. Jameson?" she said. "Loving the garlic and fresh thyme."

"It's Good Eats Forty Cloves and a Chicken." Then Rook held up the cookbook and said, "How weird is this? Alton Brown calls this the perfect make-ahead meal for those pesky serial-homicide weeks, or when you've had a long day chasing Naughty Nurses."

While they ate, they watched News 3 @ 10. Of course, the lead story was the strangulation murder of their consumer advocate, Maxine Berkowitz. Greer Baxter's stoic reading was offset by video of WHNY staffers in tears and a live shot from 72nd and Riverside Drive, where the field reporter, standing before a makeshift curbside memorial of candles and flowers, showed the crime scene, which police had cordoned off waiting for a daylight evidence search. The reporter said, "NYPD Captain Wallace Irons is with me. He is commander of the Twentieth Precinct."

"He's also the shortest distance between a body bag and a TV camera," heckled Rook as Wally stepped into the bright lights beside the reporter.

Irons kept his appearance basically ceremonial. When Heat had briefed him a half hour before, she gave him the fundamentals: cause of death, time of death, and how the body had been discovered. He used his airtime as a plea for eyewitnesses to come forward, as she had coached him to do. Nikki had not, however, told Irons about the string. Or that this likely was the work of a serial killer. She would do that first thing in the morning. But for now she held it back simply because she did not trust her commanding officer's big mouth.

After dishes, they uncorked an Haute-Cotes de Nuits then time traveled to 1999. Joe Flynn's surveillance photos of her mother made it an emotional trip for Nikki. The private eye's telescopic lens captured Cynthia Heat just as her daughter remembered her: sleek, elegant, and poised. Nikki's dad had commissioned the tail, suspecting his wife of having an affair, and not without cause. Cindy Heat's moves were all about hiding a secret life-from her husband and from her own kid. Nikki and her father never discussed it. They were each afraid to give it voice, but they both suspected her of hiding something. Both had no idea it was a double life as a CIA operative spying on the families that hired nice Mrs. Heat to tutor piano. Nikki reflected on the irony that a husband's worry about a cheating spouse led him to hire a private investigator whose creeper photos might now give up clues to a rogue ex-CIA conspiracy.

Nikki had loaded the thumb drive Flynn gave her onto Rook's MacBook Pro and, shoulder-to-shoulder, they watched the slide show on its monitor. Once Nikki got past the nostalgia of seeing eleven-year-old images of her mom, she focused on the other faces. Some pictures were peep-shots taken through windows into homes; most were taken on Manhattan sidewalks as the tutor-under-surveillance arrived or departed with binders of sheet music under one arm. Heat recognized the Jamaican, Algernon Barrett, who had been ducking behind his lawyer's skirts to avoid her. One shot captured Cynthia with the brewery tyc.o.o.n Carey Maggs, sitting on the planter outside his apartment building, laughing at something his little boy must have just said. More pictures of the same ilk flashed by. Vaja Nikoladze's Rudolf Nureyev mop of hair dated the photo of him chatting with Cindy Heat on the gravel drive of his Hastings-on-Hudson property. A Georgian shepherd pup sat obediently by his left leg.

Rook fast-clicked through a series of duplicate shots, but when Nikki said "Whoa," he paused the slide show and they stared at the familiar face of the man in deep conversation with Cindy Heat on a Midtown sidewalk. They didn't know his name, but they would never forget him. He was the doctor who, three weeks prior at a Paris hospital, had helped Tyler Wynn fake his death in front of Heat and Rook. "Holy f.u.c.k," said Rook under his breath.

"Curiouser and curiouser," agreed Nikki. "One more picture, let's see it."

Cynthia Heat was not in the next shot, but the French doctor was-in the front seat of a parked car with another man they didn't recognize. Rook said, "Looks like our French doc spent enough time around your mom to earn some photo ops." Nikki jotted down the date and time of the picture so she could call Joe Flynn to ask if he had an ID on either man. When she finished, she found Rook staring at her. "I have an idea you are going to hate."

"You're right," she said, "I hate it." Nikki settled onto the couch in his great room with the million-dollar view of the Tribeca skyline and added, "What world do you live in that you think I could just drop everything and go to Paris?" He brought over the bottle of wine and their gla.s.ses, and while he set them on the coffee table, she continued, "If this is some covert plan of yours to whisk me away to safety, it's a debatable strategy, Rook. I can get poisoned at a zinc bar on the Left Bank just as easily as at the Gramercy Starbucks."

"First of all, this isn't some covert plan. It's just something I've been thinking about secretly." He realized what he had just said and held out her wine. "Let me finish. What I mean is that ever since Tyler Wynn escaped, I've been considering a trip back to Paris to see if I can pick up his trail on his old stomping grounds. Maybe even recontact my Russian spook pal, Anatoly. That's not covert; those are just inner thoughts I didn't express."

"Something very new for you," she said as she took a sip of her Burgundy.

"Come on, Nik, now that you've seen that French doctor with your mom in those old pictures, isn't one investigative bone in that body of yours aching to find the connection?"

"Well. I have been thinking the same thing."

"Covertly?"

"Shut up."

"A moment, while I savor this rare t.i.t-for-tat victory." He closed his eyes, smiled, then opened them. "OK. Here's what I want to do. I want to show up at that Paris hospital, surprise Dr. McFrenchie, and see what he knows about Tyler Wynn, then and now."

Nikki sat upright and rested her gla.s.s on the coaster. "You know, I'm hating this less."

"So you do see the logic of going?" he asked. When she said she did, he pressed it. "And you'll come?"

"Get real, Rook. I can't get away."

"Not even for a working trip?"

She smoothed his collar then left her hand draped on his chest. "May I point out I have plenty of loose ends I'm working right here, including a fresh trail to Salena Kaye? Not to mention a little thing that's come up called a serial homicide."

"It's always something," he said, kidding, but only sort of.

Nikki nodded to herself, reaching a decision. "You go. But answer this: Are you trying to help me solve the case, or gather more material for your next article?"

Rook said, "That hurts." He stared out the window into the New York night, then said, "But I'll forgive you if we can have make-up s.e.x."

Nikki Heat called her team in for an early start. When the detectives rolled in at 6 A.M., she positioned her computer screen so she could peek at their reactions as each discovered a coffee waiting on his or her desk labeled "Nikki" in grease pencil. "You'd better laugh," she said over their chuckles. "This prank cost me twenty dollars."

Her cell phone vibed. Rook, texting that he was about to go through TSA screening for his flight to Paris, and before he jetted off, he wanted to let her know how much he enjoyed his wake-up service. Heat had slept deeply after their make-up s.e.x, descending into sweet oblivion folded into his arms. She awoke because of the morning-after soreness from her jujitsu round with Salena Kaye. Since he'd planned to get up at four to make his plane, she decided to be his alarm clock and slid under the sheets. Nikki texted back that she looked forward to his next layover and walked to the front of the squad room, but slowly enough to lose the smirk.

She'd rolled two Murder Boards side by side: one for Roy Conklin and a new one, for Maxine Berkowitz. She briefed the detectives who hadn't been on-scene at Riverside Park on the bullet points of the TV reporter's death. When Ochoa asked about boyfriend troubles, Nikki shared about the bad breakup with the news director and a.s.signed him to check out George Putnam's alibi. "Check his wife's whereabouts, too," said Heat, just in case there was a volatile side of that triangle. "But tread lightly. Let's not rule anything out, but this feels like more than a jealous payback."

That brought her to the connection between the two murders. "We have a unique telltale that indicates a serial killer." She posted blowups of CSU photos of the string found at each crime scene and then picked up her notes. "Forensics burned some midnight oil to get us some data this morning. Both the red and the yellow string are made from a braided polyester widely used for everything from hobbies and crafts, to jewelry making, to yo-yo strings and something called kendama."

Randall Feller raised a finger for attention and said, "That's a j.a.panese game that uses a wooden spindle with a cup at one end that you use to catch a wooden ball attached to it by a string." He paused only briefly and added, "Don't ask."

"Nice to know when Rook's not here there's somebody to pick up the know-it-all slack," observed Raley.

Since Detective Feller had demonstrated a special interest, Heat a.s.signed him to make checks of area hobby, craft, hardware, and toy stores to see if they had any customers worth checking out. "Detective Rhymer, you a.s.sist. I'm sure this string is also available on the Internet. Find out who sells it and contact those sites for customer records."

A civilian aide came in from the front office and handed a message to Heat, who digested it and addressed her crew. "A foot patrol making checks of trash cans discovered a three-foot coaxial cable not far from the Eleanor Roosevelt statue. Forensics has it now. It's only prelim, but there appear to be traces of makeup in the center of the cord." Heat reflected on the tissues she saw protecting Greer Baxter's collar from her TV makeup and said, "That would be consistent with our strangulation."

"What about the Rollerblade wheel?" asked Rhymer.

"Strange, isn't it?" said Heat. "The strings are plenty creepy, but the Rollerblade is weird, too. Forensics says it's a brand-new, standard polyurethane inline skate wheel, no prints, no wear. It's straight from the package." She reflected a moment and said, "Sharon?" Detective Hinesburg sat up like she'd been poked with a stick. "I'd like you to team with Raley and Ochoa and run the skate wheel."

That evening, when the shift had ended and Heat had the bull pen to herself, she embraced the stillness to contemplate the Murder Boards and let her instincts talk. The case work had not yielded any new clues, and her cop sense told her that the elimination of the few leads they had was not a negative but a means to an end. For instance, both George Putnam and his wife's alibis had been confirmed. Similarly, Roy Conklin continued to check out as a man who was easy to love but difficult to investigate for that very reason.

Nikki sat on her desktop, letting her eyes drift from board to board, letting the known elements speak the mind of a serial killer over the low hum of fluorescent tubes. String. String was the literal common thread. What else? Oddball props. A dead rat. An inline skate wheel. How were they connected? Or were they at all?

Geography. The obvious. Both victims had been found on the Upper West Side, in particular, the Twentieth Precinct-a self-canceling clue because it meant the killer lived or worked there, or else traveled there to kill away from his home base.

Minutes pa.s.sed, maybe even an hour. When Nikki got into this flow, she not only lost time, she hid from it. She reached for her notebook and wrote one word: "Jobs."

What came to her was more than just that both victims had been either mutilated or killed by an instrument related to their work: the restaurant inspector by an oven; the TV reporter by a coaxial cord, the kind used to connect cable TV. Those similarities were already top-lining the squad conversation. This was something not as obvious, but close enough. She called Roach, Feller, and Rhymer back to the precinct.

Far from being annoyed at getting boomeranged in, the four detectives gave off the edgy vibe of antic.i.p.ation, and when Heat began, "It's right in front of us. Both vics were in the business of consumer protection," she saw their eyes come alight. "I want to find out if they knew each other or if they knew someone in common." From there on, the meeting was short. She put Roach on contacting Olivia Conklin, Feller back on his beat at the Health Department, and Rhymer on Maxine Berkowitz's coworkers and friends. "Check e-mails, texts, phone records, everything that leaves a trail," she said, and watched them cancel their evenings and hit the phones with renewed purpose.

Back early the next morning, with little to go on yet much to cover, the day for all of them became the essence of good detective work: drudgery. The hours of phone calls and computer checks got broken up only by meeting up to compare notes after pounding the pavement for face time with shop owners, park nannies, and doormen who'd seen nothing out of the ordinary. The true ch.o.r.e of Nikki's day came when Captain Irons arrived in the late morning, camera-ready with a fresh white uniform shirt in dry cleaner plastic, just in case someone needed a statement. After satisfying himself n.o.body had tried to kill his lead homicide detective in the last twenty-four hours, he asked for a briefing of both active cases. Wally was more an administrator than a cop, and his eyes glazed over as she filled him in on the details. When she finished, his first question was his go-to: "How much overtime is this gonna drain from my budget?"

Always prepared for that resistance, Nikki managed to sell the precinct commander on the long-term savings of bringing in more manpower, and came out of his gla.s.s office with an OK to bring in one of her favorite detective teams, Malcolm and Reynolds.

Rook checked in from a taxi heading from Charles de Gaulle Airport to his hotel in Paris. It was night there, New York plus six, and he said he'd left word with Anatoly Kije, his old Russian spy friend, hoping they could meet for a late dinner-slash-debrief.

"You mean the same Anatoly Kije whose henchmen kidnapped us from Place des Vosges just so he could be sure we weren't being followed?"