“Where did you find that?” Hollis asked.

“In my supervisor’s locker. I kind of borrowed the keys a couple of weeks ago and copied them.”

Naz opened the door and led them into the building. They were standing on a steel floor surrounded by circuit boxes and electrical conduits; an opening in one corner led to a staircase. The door closed behind them and a loud boom echoed in the small space. Alice took two quick steps forward before controlling her fear. She looked like a half-wild animal that had just been returned to a cage.

The circular staircase went downward like an enormous corkscrew to a landing where a single lightbulb burned above a second security door. Naz sorted through his stolen keys, mumbling to himself as he tried to open the lock. Finally he found the right key, but the door still wouldn’t move.

“Let me try.” Hollis raised his left foot and aimed a front kick at the lock. The door popped open.

One by one, they entered the abandoned City Hall station. The original light fixtures were empty, but someone had attached an electrical cable to the wall and run it to a dozen bulbs. A token booth was at the center of the entrance lobby; it had a little dome-shaped copper roof and looked as if it belonged in the sort of old-fashioned movie theater that had ushers and a red velvet curtain. Beyond it were wooden turnstiles and a concrete platform by the subway tracks.

A layer of grayish-white dust covered the floor; the air was stale and smelled like machine oil. Gabriel felt as if he were locked inside a tomb until he gazed upward at the vaulted ceiling. It reminded him of a medieval church-an interior of high arches that rose from the ground and met at central points. The tunnel itself was another set of arches, illuminated by tarnished brass chandeliers that held frosted-glass globes. No advertisements. No surveillance cameras. The walls and ceilings were decorated with white, red, and dark green ceramic tiles that formed intricate geometric patterns. It made the underground environment feel like a sanctuary, a place of refuge from the disorder above them.

Gabriel felt warm air move across his skin, and then heard a distant rumble, growing in power. Seconds later, a subway train came around the curve and raced through the station without stopping.

“That’s the number six local,” Naz said. “It loops through here and heads back uptown.”

“Is that how we get to Grand Central?” Sophia asked.

“We’re not riding on the six. It’s too public.” Naz glanced at his watch. “You get a private train with nobody watching. Just wait. Devon should be here in a few minutes.”

Naz paced in front of the booth, and then looked relieved when a pair of headlights appeared in the tunnel. “Here he comes. I need the first thousand-right now.”

Vicki handed a wad of hundred-dollar bills to Naz, and their guide passed through a wooden turnstile to the platform. He waved his arms as a single subway car rolled into the station pulling a hopper car piled high with trash bags. A slender black man-well over six feet tall-was operating the controls in the front cab. He stopped the subway car and opened the double doors. Naz shook hands, exchanged a few words, and then handed the money to his friend.

“Hurry up!” he shouted. “Another train will be here in a minute.”

Maya led the group into the subway car and told them to sit at either end, away from the windows. Everyone obeyed her-even Alice. The little girl seemed completely aware of everything that was going on, but she never showed any expression.

Devon stood in the doorway of the closet-sized cab. “Welcome aboard the trash train,” he said. “We got to change tracks a couple times, but we’ll be up at Grand Central in about fifteen minutes. We’ll stop at a maintenance platform because there aren’t any TV cameras in that area.”

Naz was grinning as if he’d just performed a magic trick. “See? What’d I tell you?”

Devon pushed the control lever down and the train jerked forward, picking up speed as it left the abandoned station. The car rocked back and forth, and then they were heading north beneath the streets of Manhattan. Devon stopped at the Spring Street station, but didn’t open the doors. He waited until a green light flashed in the tunnel, then pushed the lever again.

Gabriel got up from his seat and stood next to Maya. The window in the door was open a few inches and warm air pushed into the car. As the train shifted onto a new track, it felt as if they were traveling through a secret part of the city. Light appeared in the distance, reflected on the tracks; there was a clattering sound and then they glided slowly through the Bleecker Street station. Gabriel had traveled on the east-side line several times before, but this experience was different. They were safe within a shadow land, one step beyond the scrutiny of the Vast Machine.

Astor Place. Union Square. And then the door to the control room popped open. The train was still moving, but Devon wasn’t touching the controls.

“Something’s going on…”

“What’s the problem?” Maya asked.

“We’re a maintenance train,” Devon said. “I’m supposed to be running it. But the computer took over when we left the last station. I tried to contact the command center, but the radio’s dead.”

Naz jumped up and raised both hands as if he were trying to stop an argument. “It’s no big deal. There’s probably another train up the line.”

“If that was true, then they would have stopped us at Bleecker.” Devon stepped back into the control room and moved the lever again. The subway car ignored his efforts and passed through the Twenty-third Street station at the same moderate speed.

Maya drew the ceramic gun she had taken from Aronov. She kept the weapon pointed at the floor. “I want the train stopped at the next station.”

“He can’t do that,” Naz said. “The computer is running everything.”

Everyone was standing now-even Sophia Briggs and the girl. They held on to the poles in the middle of the car as lights flashed through the windows and the wheels clicked like a ticking watch.

“Is there an emergency brake?” Maya asked Devon.

“Yeah, but I don’t know if it will work. The computer is telling the train to keep moving.”

“Can you open the doors?”

“Not unless the car has stopped. I can release the safety lock and you can open them manually.”

“Good. Do that right now.”

Everyone looked out the window as they rolled through the Twenty-eighth Street station. The few New Yorkers standing on the platform looked as if they were frozen within that instant of time.

Maya turned to Hollis. “Push the door open. When we reach Forty-second Street, we’re going to jump.”

“I’m staying on the train,” Naz said.

“You’re coming with us.”

“Forget that. I don’t need your money.”

“I wouldn’t worry about the money right now.” Maya raised the gun slightly, pointing it at Naz’s kneecap. “I want to keep away from the cameras and get on that train at Grand Central Terminal.”

Devon switched off the safety lock as they left the Thirty-third Street station. Hollis forced back two of the side doors and held them open. Every few yards they rattled past a steel I-beam holding up the tunnel ceiling. It felt like they were traveling down an endless passageway with no way out.

“Okay!” Devon shouted. “Get ready!” There was a red lever with a T-shaped handle mounted on the wall of the car’s control room. Devon grabbed the handle, pulled down hard, and there was a screeching sound of steel scraping against steel. The subway car began to shiver but the wheels kept turning. As they approached Forty-second Street, the New Yorkers waiting in the station backed away from the edge of the platform.

Alice and Sophia jumped first, followed by Vicki, Hollis, and Gabriel. The train was going slowly enough that Gabriel managed to stay on his feet. Looking up the concrete platform, he saw Maya pull Naz out the open door. The wheels of the train kept screeching as it disappeared into the tunnel. People on the platform looked startled, and one man punched out a number on his cell phone.