Even on a Sunday night, the place was filled to capacity. With Jordan leading the way, the girls nestled into a pocket of space adjacent to the dance floor. Stefanie had taken only one sip of the club’s signature martini-a toxic concoction that tasted like Robitussen-infused lemonade-before she noticed Chelsea talking to a guy with blond floppy hair. Catching her eye, Chelsea pointed excitedly to the white curtains that set off a VIP lounge from the rest of the club, then disappeared through the curtains behind the blond.

Stefanie hesitated. She hated the way her friend was so open with strangers. Chelsea, despite her occasional lapses in judgment, was a good and decent person at heart, and so she automatically-and carelessly-assumed the same of others. Still, as usual, Stefanie and Jordan followed Chelsea where she wanted to go.

Stefanie began to sense what was coming around one o’clock, when she noticed both the time and Chelsea’s glassy-eyed wobble. She pointed to her watch, but the gesture proved too subtle. Forty-five minutes later, she went so far as to follow Chelsea onto the catwalk to tell her it was time to go home. The only reward for her efforts was two songs’ worth of swaying her hips with her hands undulating stupidly above her head.

Finally, at two-thirty, even Jordan was done. She joined Stefanie in the backward time calculations. Seven a.m. flight. At the airport by six. In a cab by five thirty. Wake-up call at five-five fifteen at the very latest-if they packed tonight and skipped showers. They’d get little better than a two-hour nap if they left right now. It was definitely time to call it a night.

Stefanie found Chelsea dancing on a banquette, her floppy-haired companion replaced by a tall, skinny guy with an angular face. He was passing Chelsea another highball glass. Chelsea grabbed Stefanie’s hand and tried to coax her onto the banquette, but Stefanie matched the gentle force of the tug until Chelsea simply pulled her hand away.

“Come on, Chels,” Stefanie yelled over the music. “We still need to pack. Let’s go.”

Chelsea looked at her watch, then grimaced and shrugged. “No point in sleeping now. Looks like we better make it an all-nighter.”

“Two against one.” Stefanie used her index finger to pull back the curtain closing off the private room so Chelsea could see Jordan slumped over her black patent leather clutch purse on an ottoman. “You’re the weak link. Time to go, babe.”

She pulled again at Chelsea’s hand, and once again, Chelsea jerked away. Stefanie heard a male voice ask, “Why do you have to be such a drag?”

She turned to take a closer look at Chelsea’s most recent dance partner. He was about six feet tall, probably in his mid-twenties. His brown hair was gelled into a fauxhawk. He wore straight black pants, pointy black shoes, and a white shirt with a thin black tie. Stefanie shot him her best death stare, then returned her attention to Chelsea.

“Seriously? You’re costing us precious minutes of REM sleep for Duran Duran here?”

“You mean Jake? He looks like Jake Gyllenhaal, don’t you think?”

Stefanie didn’t waste another second on the guy. “We’ve had a good run, Chels. But really, we’re leaving.”

“Go ahead,” Chelsea yelled. “I’ll be fine.”

Stefanie stole another look at Jordan, who was on the verge of sleep despite the thumping bass notes vibrating through the glossy white wood floors.

“Don’t be ridiculous. We’re not leaving without you.”

“I’m fine. I’ll be back in time for the flight. I promise.” Chelsea downed the last of her drink, gave her a Girl Scout’s pledge sign, then brought her hand down for a mock booty slap.

Stefanie couldn’t help but smile at Chelsea’s goofy moves. “Please tell me you’re not leaving with New Wave Boy.”

Chelsea laughed. “Of course not. I’ll take a taxi. I just want to dance a little longer. This is like, the best night ever.”

Stefanie looked around the club and realized she had no hope of persuading Chelsea to leave with them.

“You’ve got cash?”

Chelsea jumped off the banquette and gave Stefanie a quick hug. “Yes, Mom. And credit cards.”

“We can’t miss our flight,” Stefanie warned.

“Obviously not. I’ll come straight back, closing time at the very latest, right?”

Following Jordan out the double doors of Pulse, Stefanie tried to settle the uneasy feeling she still carried. Last call was in an hour. What was the worst that could happen?

She did not notice the blue Ford Taurus parked half a block down. Nor could she know how happy the car’s driver was to see the two brunettes leave in a cab together, without their friend.

THEY SAY NEW YORK is the city that never sleeps, but Ellie Hatcher knew it got pretty drowsy around five in the morning. So did she.

“Wake up.”

Ellie felt her sticky eyelids flutter open, then immediately fall shut, shielding her from the sliver of brightness peeking into her bedroom through the unwelcome crack in the door. The crack widened into a flood of white light, and she pulled her comforter over her head.

“Unngh,” she groaned under the safety of the navy-blue down.

She felt something hit her right hip, then heard her brother’s voice. “Get up, El.”

Jess sounded annoyingly chipper, so Ellie did what any sane person would do in the face of such early-morning cheer. She ignored him.

Another quick thump, this time dangerously close to her head.

Ellie threw the comforter aside, tossing the source of the two thumps-a pair of Saucony running shoes-to the parquet floor. “Go away,” she muttered, burrowing back into the covers.

“This is your own fault,” Jess said, tugging at the socked foot she’d managed to leave unprotected. “I believe you threatened to charge me rent if I didn’t wake you up today. This was your pact: skip no more than twice a week, and never two days in a row. Sound familiar? You slept in yesterday.”

The worst part of having your own words thrown back at you, Ellie decided, was that you couldn’t argue with them.

THEY RAN IN SILENCE for the first two and a half miles.

They had struck this deal three weeks earlier. For Ellie, the 5:00 a.m. runs were the start of an early morning; for Jess, the end of a late night at work. And for both, the exercise was a means of counteracting the cigarettes and alcohol for which they seemed to reach so frequently these days. And because Ellie was best at sticking to rituals that were clearly defined, there were rules: They could skip up to twice a week, but never twice in a row.

Jess had come to learn another, less explicit rule: these runs were not a time to discuss her recent trip back to their hometown of Wichita, which they both knew-but never acknowledged-was the true reason Ellie needed this solitary routine to mark each new day.

This particular morning, however, they were not the only ones in East River Park.

“So what do you think’s going on over there?” Jess asked.

Ellie followed her brother’s gaze to a group of three men gathered at the fencing that surrounded a small construction site next to the FDR Drive. The men wore T-shirts and running shorts and had the long, lean frames typical of serious runners. One of the guys also wore a fanny pack and was speaking into a cell phone. Ellie couldn’t make out the man’s words from this distance, but she could see that his two companions-peering through the honeycomb mesh-were shouting information to him.

She also detected the high-pitched jingling of an electronic gadget. Something about the melody was familiar.

“Don’t know, don’t care.” Ellie just wanted to get home, catch her breath, and give her legs a rest. The construction site had been there on the west side of the park since they had begun their routine. For Ellie, the only significance of the location was its proximity to the Williamsburg Bridge, the official turnaround point on their established route. Her sole focus remained on the path in front of her-the tennis courts were a few yards ahead, followed by the bridge, then it was time to head back.