“We’re investigating,” Nash sputtered. “Mr. Boone is dealing with the problem and he assures me that-”

Michael interrupted. “The Shadow Program will fail-all of your programs will fail-unless you find my father. You know that he started the New Harmony community in Arizona. Who knows what other centers of resistance he has started-or is organizing right now?”

A tense silence engulfed the room. Looking at the faces of the Brethren, Michael knew that he had managed to manipulate their fear.

“So what are we supposed to do?” Jensen asked. “Do you have any ideas?”

Michael bowed his head like a humble servant. “Only a Traveler can find another Traveler. Let me help you.”

On Flatbush Avenue in Brooklyn, Gabriel found a storefront travel agency with a dusty collection of beach toys displayed in the front window. The agency was run by Mrs. Garcia, an older Dominican woman who weighed at least three hundred pounds. Chattering in a mixture of English and Spanish, she pushed at the floor with her feet and scooted around the room in an office chair with squeaky wheels. When Gabriel said that he wanted to buy a one-way ticket to London-paying in cash-Mrs. Garcia stopped moving and studied her new customer.

“You have a passport?”

Gabriel placed his new passport on the desk. Mrs. Garcia inspected it like a customs official and decided that it was acceptable. “A one-way ticket makes questions with inmigración y la policía. Maybe questions no good. Sí?”

Gabriel remembered Maya’s explanation of air travel. The people who got searched were grandmothers carrying fingernail scissors and other passengers who violated simple rules. While Mrs. Garcia rolled over to her desk, he checked the money in his wallet. Buying a round-trip ticket would leave him about a hundred and twenty dollars. “All right,” he told her. “Sell me a round-trip ticket. On the first flight out.”

Mrs. Garcia used her personal credit card to buy the ticket, and she gave Gabriel information about a hotel in London. “You don’t stay there,” she explained. “But you must give el oficial del pasaporte an address and phone number.” When Gabriel admitted that he didn’t have any luggage other than his shoulder bag, the travel agent sold him a canvas suitcase for twenty dollars and stuffed it with some old clothes. “Now you are a tourist. So what do you want to see in England? They might ask you that question.”

Tyburn Convent, Gabriel thought. That’s where my father is. But he shrugged his shoulders and looked down at the scuffed linoleum. “London Bridge, I guess. Buckingham Palace…”

“Bueno, Mr. Bentley. Say hello to the queen.”

Gabriel had never flown overseas before, but he had seen the experience in movies and television commercials. Well-dressed people were shown lounging in comfortable seats, where they had conversations with other attractive passengers. The actual experience reminded him of the summer he and Michael had spent working at a cattle feed lot outside of Dallas, Texas. The cattle had bar-coded tags stapled to their ears, and a great deal of time was spent picking out the steers that had been there too long, inspecting them, weighing them, sorting them into pens, driving them down narrow chutes, and forcing them into trucks.

Eleven hours later, he stood in the customs line at Heathrow Airport. When it was his turn, he approached the passport officer, a Sikh with a full beard. The officer took Gabriel’s passport and studied him for a moment.

“Have you ever visited the United Kingdom?”

Gabriel offered the man his most relaxed smile. “No. This is my first time.”

The officer ran the passport through a scanner and studied the screen before him. The biometric information on the RFID chip matched the photograph and the information already placed within the system. Like most citizens in a dull job, the officer trusted the machine more than his own instincts. “Welcome to Britain,” he said, and suddenly Gabriel was in a new country.

It was almost eleven o’clock at night when he changed his money, left the terminal, and took the Tube into London. Gabriel got off at King’s Cross station and wandered around the area until he found a hotel. The single room was as big as a closet and frost crystals were on the inside of the window, but he kept his clothes on, wrapped himself in the thin coverlet, and tried to sleep.

Gabriel had turned twenty-seven a few months before he left Los Angeles. It had been fifteen years since he had seen his father. His strongest memories came from the period in which his family lived without electricity or telephones on a farm in South Dakota. He could still recall his father teaching him how to change the oil in the pickup truck, and the night that his parents danced with each other beside the firelight in the parlor. He remembered sneaking downstairs at night when he was supposed to be in bed, peering through the doorway, and seeing his father sitting alone at the kitchen table. Matthew Corrigan looked thoughtful and sad at those moments-as if an immense weight had been placed on his shoulders.

But most of all, he remembered when he was twelve and Michael was sixteen. During a heavy snowstorm, Tabula mercenaries attacked the farmhouse. The boys and their mother hid in the root cellar while the wind howled outside. The next morning, the Corrigan brothers found four bodies lying in the snow. But their father was gone, vanished from their lives. Gabriel felt as if someone had reached into his chest and removed some part of his body. There was an emptiness there, a hollow feeling that had never quite gone away.

WHEN HE WOKE up, Gabriel got directions from the hotel clerk and began to walk south, to the Hyde Park area. He felt nervous and out of place in this new city. Someone had painted LOOK LEFT or LOOK RIGHT at the intersections, as if the foreigners who filled London were about to be crushed by the black cabs and white delivery vans. Gabriel tried to walk a straight line, but he kept getting lost on narrow cobblestone streets that went off at odd angles. In America, you carried dollar bills in your wallet, but now his pocket was heavy with coins.

Back in New York, Maya had talked about the vision of London that she had learned from her father. Apparently, there was a patch of ground near Goswell Road where thousands of plague victims had been dumped into a pit. Perhaps a few bones were left, a coin or two, a metal cross once worn around a dead woman’s neck, but this burial ground was now a car park decorated with billboards. There were similar places scattered around the city, sites of death and life, great wealth and even greater poverty.

The ghosts still remained, but a fundamental change was taking place. Surveillance cameras were everywhere-at traffic intersections and inside shops. There were face scanners, vehicle readers, and doorway sensors for the radio-frequency ID cards carried by most adults. The Londoners streamed out of the Tube stations and walked quickly to work while the Vast Machine absorbed their digital images.

Gabriel had assumed that Tyburn Convent would be a gray stone church with ivy on the outer walls. Instead, he found a pair of nineteenth-century row houses with leaded windows and a black slate roof. The convent was on Bayswater Road, directly across the street from Hyde Park. The traffic grumbled toward Marble Arch.

A short metal staircase led to an oak door with a brass handle. Gabriel rang the doorbell, and an elderly Benedictine nun wearing a spotless white habit and a black veil answered the door.

“You’re too early,” the nun announced. She had a strong Irish accent.

“Early for what?”

“Oh. You’re an American.” Gabriel’s nationality appeared to be all the explanation that was necessary. “Tours of the shrine start at ten o’clock, but I suppose a few minutes don’t matter.”