HER CALLS TOOK less than three minutes. CSU would be ready for an initial briefing from the crime scene in an hour. The ME needed two.

Rogan was still on the phone. He had his head down, eyes closed-right hand on the handset, the other massaging his left temple. It was as if he were picturing himself outside this room, away from New York City, standing on a front porch with two parents in Fort Wayne, Indiana. Ellie could almost imagine Rogan looking Mr. and Mrs. Hart in the eye and breaking the news: Your daughter was supposed to take a cab back to the hotel, but she never arrived.

The image gave her an idea. She opened Internet Explorer on her computer, Googled the New York City Taxi and Limousine Commission, and dialed the telephone number listed on the commission’s Web site.

For decades, drivers of New York City’s taxis had maintained their trip sheets by hand, using pen and paper to log the location and amount of each fare. Trying to track down a cab driver on the basis of paper trip sheets was like searching for the proverbial needle in a haystack of thirteen thousand yellow cabs.

The tide in the sea of paper had shifted just last year, however, when the city’s new high-tech requirements for all medallioned cars had gone into effect. Although a few drivers remained at war with the commission over the expensive technology, a critical mass of taxis was now equipped with computers that not only accepted credit card payments but also used GPS technology to automate the ancient trip sheet practices. Obtaining a list of the cabdrivers within a one-block radius of Pulse around the time of last call would have once been impossible; now it was just a matter of a few keystrokes on a computer.

Ten minutes later, they had finished their calls. Rogan had learned that Chelsea’s parents would be coming to New York City on the next available flight. Ellie had faxed a photograph of Chelsea Hart to be circulated among cabdrivers who’d picked up early-morning fares in the Meatpacking District. And the lives of Paul and Miriam Hart were forever changed.

THE PROCESSING of the East River Park crime scene was in full swing. NYPD vans lined the park, backing up traffic on the FDR in both directions as drivers slowed to rubberneck. Yellow police tape, fortified by rows of uniform officers, closed the park from Sixth Street down to Cherry.

They badged an officer standing guard north of the tennis courts, ducked beneath the yellow tape, and made their way to the construction site. Ellie had never been here in full daylight. Torn up and cluttered with piles of dislodged dirt, backhoes, and other heavy equipment she couldn’t name, this area of the park would have been almost as desolate as it had been during her early-morning runs, were it not for the chaos of the ongoing police investigation.

Four officers were working the scene inside the fence. Rogan headed directly for a tall female officer with long red hair pulled into a braid that ran down her back. She was crouched in a squat, using tweezers to place something in a ziplock baggie.

“Is that Florkoski?”

The woman sealed the evidence collection bag and eased herself back to standing. She had a broad face that broke into a friendly smile at the sight of Rogan.

“Hey there, Double J. Good to see you.” She snapped a latex glove off of her right hand and extended it for a shake, first to Rogan and then to Ellie. “Mariah Florkoski.”

“Ellie Hatcher,” Ellie said, returning both the smile and the handshake.

“New partner,” Rogan said.

“Oh, sure.” Florkoski nodded. “I recognize the name.”

Ellie had no doubt that the recognition was due to her one and only previous homicide case two months earlier, when she had been recruited to help investigate a series of murders tied to an Internet dating company. By the time the case was solved, a serial killer was arrested, a Russian identity-theft ring was busted, and one of the best cops Ellie would ever know was dead. And apparently other cops knew her name as a result.

“What happened to Casey?” Mariah asked.

“Retired. Last month.”

“Don’t tell me. He’s finally going to Scottsdale.”

“The movers are coming next week.” Rogan turned to Ellie and explained. “My last partner. Jim Casey. He’d tell anyone who’d listen he was retiring to Arizona.”

“That his only wish was to die on a Scottsdale golf course,” Mariah said.

“With a gin and tonic in hand,” Rogan added.

“You getting along all right without him?”

“Hatcher here’s good peeps.”

Ellie gave a tiny mock bow of gratitude.

“Well, at least you didn’t wind up with that lazy slug Winslow.”

Ellie struggled to place the name, then remembered Lieutenant Eckels’s remark-that she would have been the one stuck with Winslow if it hadn’t been for Rogan.

“I take it this case belongs to the two of you?”

“What have you got so far?” Rogan asked.

“Well, I can tell you the vic wasn’t killed here.”

Rogan’s lips set into a line of disappointment. All crime scenes were important. Any could yield evidence. But it was the primary crime scene that was most likely to yield blood, saliva, semen, hair, fibers, and fingerprints-all of the physical evidence that jurors increasingly insisted upon, now that the fictional world of the multiple CSI shows had become ingrained in the minds of ordinary people.

Mariah pointed to a male officer who was photographing the dirt in front of him. “We’ve got a whole bunch of footprints in the area in front of her body-all with treads, consistent with athletic shoes. But fortunately, our runners didn’t crowd the body. They gave her some space. Closer in to the corpse, we’ve got another set of footprints-smooth bottomed, not likely an athletic shoe-pointing into and then away from the body. One guy. He carried her in, dropped her, then walked out.”

“Any chance you’re going to tell us the shoe is one of a kind,” Rogan said, “custom-made at the foot of the Swiss Alps?”

Mariah smiled and shook her head. “It looks like any footprint you’d see on a Ballroom Dancing 101 instruction chart. Oval toe, square heel. No markings. About as generic as it gets.”

“How do you know she didn’t walk over here with him, then he walks out alone?” Rogan asked.

“Chelsea was wearing high heels,” Ellie said.

“Lucky for us.” Mariah walked a few feet to a blue plastic storage bin resting on the ground just beyond the yellow crime tape. She reached in and pulled out a larger baggie containing a pair of high-heeled sandals. Ellie recognized them as the shoes Chelsea had been wearing that morning.

“These bad boys would have left behind an imprint like a big exclamation point.”

“Anything else?” Rogan asked.

“We picked up a bunch of garbage lying around-Coke cans, cigarette butts, that kind of crap. We’ll look for prints. Have you guys talked to the ME yet?”

“Next stop,” Rogan said.

“Well, I’ve got one piece of good news for you. I took the shoes, but the ME took the clothes. But before they carried the vic away to the bus, I dusted her shirt. I pulled one latent off the underside of the top button of her blouse.”

“Chances are, she was the one to leave it behind.”

Mariah nodded. “Probably, but that’s not the best part.” She paused to make sure she had their full attention. “When I was working on her blouse, I saw a stain that may or may not have been seminal fluid.”

Rogan rubbed his palms together. “Now that’s what I’m talking about.”

“Don’t go getting too excited. The girl could’ve dripped a smoothie on herself, for all I know. I can run the print in a couple of hours, see if there’s a match in the database. The stain-I can tell you within a day or so whether it’s bodily fluid or Tasti-Delite. But if it’s the former, it’ll take a good couple of weeks before we get DNA back.”