Gabriel knew that the crisis now facing Britain was many years in the making and, to a large degree, self-inflicted. For two decades, beginning in the 1980s and continuing even after the attacks of 9/11, British governments both Labour and Tory had thrown open their doors to the world’s most hardened holy warriors. Cast out by countries such as Egypt, Saudi Arabia, Jordan, and Syria, they had come to London, where they were free to publish, preach, organize, conspire, and raise money. As a result, Great Britain, the land of John Locke, William Shakespeare, and Winston Churchill, had unwittingly allowed itself to become the primary incubator of a violent ideology that sought to destroy everything for which it had once stood. The British security and intelligence services, confronted by a gathering storm, had responded by choosing the path of accommodation rather than resistance. Extremism was tolerated so long as it was directed outward, toward the secular Arab regimes, America, and, of course, Israel. The failure of this policy of appeasement had been held up for all the world to see on July 7, 2005, when three bombs exploded inside the London Underground and a fourth tore a London city bus to shreds in Russell Square. Fifty-two people were killed and seven hundred more wounded. The perpetrators of this bloodbath were not destitute Muslims from abroad but middle-class British boys who had turned on the country of their birth. And all evidence suggested it was only their opening salvo. Her Majesty’s security services estimated the number of terrorists residing in Britain at sixteen thousand—three thousand of whom had actually trained in al-Qaeda camps—and recent intelligence suggested that the United Kingdom had eclipsed America and Israel as al-Qaeda’s primary target.

“It’s funny,” said Seymour, “but when we checked the manifest for the flight from Amsterdam we didn’t see anyone on the list named Gabriel Allon.”

“Obviously you didn’t look hard enough.”

The MI5 man held out his hand.

“Let’s not do this, Graham. Haven’t we more pressing matters to deal with than the name on my passport?”

“Give it to me.”

Gabriel surrendered his passport and stared out the window at the traffic rushing along the A4. It was 3:30 in the afternoon and already dark. No wonder the Arabs turned to radicals when they moved here, he thought. Perhaps it was light deprivation that drove them to jihad and terror.

Graham Seymour opened the passport and recited the particulars. “Heinrich Kiever. Place of birth, Berlin.” He looked up at Gabriel. “East or West?”

“Herr Kiever is definitely a man of the West.”

“We had an agreement, Allon.”

“Yes, I know.”

“It stated that we would grant you absolution for your multitude of sins in exchange for a simple commitment on your part—that you would inform us when you were coming to our fair shores and that you would refrain from conducting operations on our soil without obtaining our permission and cooperation beforehand.”