The party had been going for six hours when Julian Ashworth III decided it was time to begin. He stood on the balcony of his Long Island estate, looking down at the crowd below—hundreds of people in silk and sequins, dancing to a jazz band that played with the desperate energy of people who knew, on some level, that none of this would last.

Julian had once believed in things. Not big things—religion, destiny, the American Dream were too vulgar for him—but small things. The thing that made a martini perfect. The thing that made a woman's laugh sound like music. The thing that made a summer evening on the coast feel like it might go on forever.

He had believed in his daughter, Lily, most of all. She was twenty-two, all sharp edges and bright eyes, the kind of young woman who could walk into a room and make everyone else feel like they were fading into the wallpaper. She worked at a gallery that showed paintings Julian couldn't afford and didn't understand, but he was proud of her, in the way that men like him showed pride—by buying her things and hoping that was enough.

It hadn't been enough. Three weeks ago, she'd gone to a club on Forty-Sixth Street. She'd left at two in the morning, drunk but coherent, and walked into an alley where a man had waited for her. She'd fought. She'd screamed. Someone had heard, or thought they'd heard, but by the time anyone came looking, she was gone.

Not dead—gone. She'd stumbled out of the alley an hour later, bleeding and broken, and made it to a hotel on Seventh Avenue where she'd collapsed on the floor and bled until she couldn't anymore.

Julian had money. He had power. He had connections that stretched from City Hall to the Supreme Court. And he had used none of it, because the man who had hurt Lily was nobody—some kid from the Bronx with a record and a gun—and nobody mattered except people like Julian.

So Julian had done something else. He had spent three weeks planning, and now he was ready.

He went downstairs, kissed his wife on the forehead (she was dancing with a man half her age, which was fine—Julian didn't care about anything except one thing), and walked out the side door into the garden.

The garden led to a wine cellar that Julian had converted into a private room. Inside, Freddy Malone sat bound to a chair. Freddy was a jazz musician—a saxophone player who had once played at Julian's parties, who had drunk his wine and laughed at his jokes and called him "sir" in a voice that was equal parts respect and mockery.

Freddy had also been the man who'd walked past the alley on the night Lily died. He'd seen her. He'd heard her. And he'd kept walking, because he was Freddy Malone, and Freddy Malone was a coward.

"You know why you're here," Julian said.

Freddy nodded. He was drunk, but not drunk enough to be unconscious. Julian had paid the bartender at the Blue Note to make sure of that.

"I didn't mean to," Freddy said.

"I know," Julian said. "That's the problem. You didn't mean to. And that's what I need to understand—whether a world where people don't mean to do terrible things is a world worth living in."

He pointed to the device beside Freddy—a gramophone arm modified with a steel point, set to descend slowly over the course of fifty minutes. At the end, it would puncture Freddy's skull.

"I've invited people," Julian said. "They'll come, one by one. They'll see what's happening. And they'll decide whether to stop it. I won't stop them. I'll just watch."

He left. The gramophone started. The steel point began its slow descent.

The first to arrive was Cleo DuMont, Julian's former mistress, now married to a man who owned half the casinos in Atlantic City. She arrived at the twelfth minute, drawn by a letter that promised "the most interesting party of the season."

She found Freddy in the cellar, bound and terrified, with a gramophone arm slowly moving toward his head. She screamed. Then she stopped screaming. Then she sat down on the stone steps and lit a cigarette.

"Go away," Freddy said.

"No," Cleo said. "I want to see how this ends."

The second to arrive was Dr. Harrington, Julian's college friend and a man who had spent the last ten years studying human behaviour at Columbia. He arrived at the twenty-fourth minute, carrying a notebook and a look of intense professional curiosity.

"Fascinating," he said, examining the gramophone arm. "A modified Victorola, I'd say. The descent rate is approximately one millimetre per minute. At fifty minutes, the point will reach the—"

"Stop talking," Freddy said.

Dr. Harrington sat down and began taking notes.

The third to arrive was a man named Tommy O'Brien, a bootlegger who supplied Julian's parties with whiskey from Canada. Tommy arrived at the thirty-sixth minute, because Cleo had sent for him, and Cleo could always count on Tommy.

"What the hell is this?" Tommy said, looking at Freddy.

"A experiment," Dr. Harrington said without looking up from his notebook.

"By whom?"

"By Julian."

Tommy spat on the floor. "That son of a bitch. He's been planning this for weeks." He looked at Freddy. "You're lucky, you know. Most people in your position would be dead."

"Is he going to kill me?" Freddy whispered.

Tommy looked at the gramophone arm, which had moved perhaps an inch in thirty-six minutes. "I don't think so. I think he wants to see what we'll do."

The fourth to arrive was Lily's best friend, a girl named Peggy who had not cried since the funeral because crying felt like giving up. She arrived at the forty-eighth minute, running down the stairs from the party above, her face a mask of fury and grief.

When she saw Freddy, she stopped. When she saw the gramophone arm, she understood.

"Julian," she said.

"He's upstairs," Cleo said. "Dancing."

Peggy walked to the foot of the stairs and looked up, through the grate in the floor, at the lights and the movement of the party above. She stood there for two minutes, watching the people who had known her friend and hadn't saved her.

Then she walked back down and sat beside Cleo.

"Forty-nine minutes," Dr. Harrington said, checking his watch.

The gramophone arm moved.

"Forty-nine and a half."

Freddy was crying now. Not from fear—from shame. He was crying because he knew, in that moment, that he would spend the rest of his life wondering whether anyone would come to save him, and the answer was no, or almost no, and that was worse than death.

"Forty-nine and three quarters."

Peggy stood up. She walked to Freddy. She looked at the bonds. She looked at the gramophone arm, which was now so close to his head that he could feel the heat of the motor.

"Forty-nine and seven eighths."

Peggy reached into her purse and pulled out a pair of scissors. She cut the bonds.

Freddy fell forward, gasping. The gramophone arm stopped—Julian had built in a manual override, and Peggy had found it without knowing.

Julian appeared at the bottom of the stairs. He looked at Freddy, who was on the floor, breathing. He looked at Peggy, who was standing with the scissors in her hand. He looked at Cleo, Dr. Harrington, and Tommy, who watched in silence.

"Thank you," Julian said. And then he walked back upstairs, to the party that was still dancing, to the wife who was still smiling, to the world that was still turning, none the wiser to the fact that in a wine cellar on Long Island, fifty minutes had changed everything and nothing at all.

Above them, the jazz band played on.