Instead he picked a random direction and started walking. The sun rose higher in the sky; the morning got hot, and humid. Samir stopped to take a drink at a water fountain. He noticed a Christian church across the street. Its front doors were propped open, and a sign proclaimed in multiple languages, ALL SOULS WELCOME.

The church’s interior was cool and dim. There was no service in progress, and despite the open invitation the place was almost deserted. As Samir sat in a pew near the back, he could see only one other person, a gray-haired Chinese woman. Her head was bowed, and at first he thought she was praying, but then he heard her snores.

He looked up at the altar and was relieved to see that it was decorated with a plain cross rather than a crucifix. The Christian habit of depicting the prophet Jesus’s tortured body was objectionable on a number of levels, and while Samir wasn’t personally offended by the practice, he did think it was creepy. The empty cross, however much it had come to be associated with terrorism in recent years, seemed far more civilized.

The hairs on Samir’s neck prickled as someone slid into the pew behind him. He told himself to stay calm. But then a hand gripped the back of his pew and a voice said in Arabic, “Aren’t you one of Lut’s friends?” which was the code phrase Idris had told him to be alert for.

Samir let out a sigh of despair. He turned around. Sitting behind him was the white Christian from the bus. The silver cross on his lapel—definitely a symbol of terror in this context—shined faintly in the churchlight.

“You?” Samir said. “You’re Qa—”

“Shut up,” said the Qaeda man. “Follow me outside.”

There was a pocket park adjacent to the church. Something about the way it was laid out—the configuration of the benches, perhaps—reminded Samir of a park in Kadhimiyah where, not long ago, two gay men caught in a tryst had been beaten by a mob.

The Qaeda agent led him behind a hedge at the back of the park, then rounded on him with his fist clenched. “Take this!”

Samir raised his arms to ward off the blow. “Wait! Wait!”

“I said take this!” The Qaeda agent slapped a cell phone into one of his upraised palms. Samir fumbled and nearly dropped it, then held it out in front of himself as though it were contaminated.

“What . . . What’s this for?”

“It’s for tomorrow. When you go out on patrol with the Marines, you’re going to bring it with you.”

Samir was shaking his head even before he thought of an argument: “I’m not supposed to have a phone with me. They told us—it’s a security risk.”

“Never mind the rules,” the Qaeda agent said. “The Humvee you’ll be riding in will probably be equipped with a broad-spectrum radio jammer, so an ordinary cell phone wouldn’t work anyway. This one’s been modified to transmit on an unblocked military frequency.”

Samir kept shaking his head. “You want me to make a call from a vehicle full of soldiers?”

“The speed dial on this phone is very simple. You don’t even need to take it out of your pocket, just leave it turned on, and then when you get the signal push two buttons. I’ll show you.”

“What signal?”

“There’ll be a billboard by the side of the road with a white cross painted on it. As soon as you pass the billboard, you’ll hit the speed dial and let it ring.”

“And what happens then?” Samir asked.

The Qaeda man showed him a picture of Malik and Jibril. This was not the same photo Samir kept in his wallet. It was a photo he’d never seen before, the boys playing in their bedroom in their new home in Basra. The picture taker, whoever he was, had been standing outside the bedroom window, at night, looking in.

“What happens then?” the Qaeda man said. “Your sons get to grow up, that’s what happens then.”

The White House was something of a letdown. Mustafa would have liked to meet the new American president, about whom he’d heard good things, but a scheduling conflict made that impossible. Absent its chief occupant, the building was just another palace, albeit more tasteful than the Hussein residence. The rose garden was pretty.

From the White House they took a driving tour of some of the Zone’s other sights, eventually circling back to the center of the Mall, where they proceeded on foot to the base of the Washington Monument. Colonel Yunus drew Mustafa’s attention to a series of pockmarks in the obelisk’s north face. These were, he explained, the result of insurgent mortar strikes, the Monument having become a target after rumors spread that Boulos al Darir was planning to use it as the gnomon for a giant Islamic prayer clock.

“False rumors?” Mustafa asked.

“Rumors,” said Colonel Yunus. “Speaking of prayer, it’s almost noon. Shall we stop back at the museum before lunch?”

They walked east along the Mall. The colonel pointed to a castle-like building which he said was another branch of the Smithsonian, dedicated to Christendom’s wars. “LBJ’s misadventures feature prominently, but there’s also quite a lot about the original crusades. It’s rather interesting to see them portrayed from the antagonists’ perspective.”

“Is the crusaders’ wing where my guest bed came from?”

“Yes.” The colonel smiled. “I rather doubt it belonged to Pope Urban, though.”

Ahead in the distance they could see the half-completed dome of the new Capitol Building. A low-flying cloud passing behind it made the dome seem momentarily whole. Mustafa’s inner ear went crazy. He stumbled and would have fallen if the colonel hadn’t caught him.

“Careful,” Colonel Yunus said. “You have dizzy spells?”

“I do get vertigo sometimes,” Mustafa told him. “But I think this is just jet lag.”

“Chronic vertigo is common here. It’s a symptom of what the doctors call Gulf Syndrome.”

“Gulf Syndrome? Like the Gulf War?”

“Yes, but also gulf in the sense of a void, a gap between the way things are and the way instinct says they should be. The sense of dislocation is difficult to describe exactly, but once you’ve felt it—”

“I have felt it,” Mustafa said. “I think my father has, too.”

The colonel nodded. “I’d heard that there were cases of the Syndrome back in Arabia. Here though it’s much more pervasive. Almost everyone experiences it to some degree.”

“What do you do for it?”

“Valium helps, supposedly. Also certain antihistamines. For myself I prefer a more natural remedy.”

“And what is that?”

“Devotion to God, five times a day,” the colonel said. “Not quite as potent as benzodiazepine, perhaps, but it has other benefits.”

Mustafa snuck another look at the Capitol, and this time when his balance wavered, he knew it wasn’t jet lag. Forcibly shifting his attention, he said: “It really is different here, isn’t it? So many trees, Gaddafi would be jealous.” Glancing up at the sun: “Even the summer heat feels different.”

“I’ll tell you something funny, it’s not the climate or the country I find alien, it’s the war.” The colonel shook his head. “I really should be used to it by now. This is my fifth tour of duty. I’ve been here so long, when I think about Arabia, it’s not just like another lifetime, it’s like I was never there at all.”

“Maybe you should take a leave,” Mustafa suggested. “Go back home, get reacquainted with the place.”

“No, I’m here for the duration, now . . .” A tremor went through him that he did not seem to notice. “You know, I have these dreams sometimes, very vivid, you’ll probably get them too if you stay here long enough.”

“Dreams about what?”

“About being an American citizen . . . This one dream in particular, I have it over and over. I dream that I’m a civilian only pretending to be a soldier. It’s outdoors in a big field, at a place called Manassas. I’m there with other Americans, professionals mostly—doctors, lawyers, defense contractors . . . We dress in these costume uniforms, some blue, some gray, and stage mock battles, ‘fight’ for freedom. Then at the end of the day we go to a tavern and drink beer—mine is nonalcoholic. And then I get in my car and drive back to Alexandria . . .”