In truth, he had survived the incident without a scratch, which was his knack. His first instinct was to radio his base and request extraction. Instead, enraged by the incompetence of his superiors, he started walking. Concealed beneath the robe and headdress of a desert Arab, and highly trained in the art of clandestine movement, he made his way through the coalition forces and slipped undetected into Syria. From there, he hiked westward across Turkey, Greece, and Italy until finally he washed ashore on the rugged island of Corsica, where he fell into the waiting arms of Don Anton Orsati, a crime figure whose ancient family of Corsican bandits specialized in murder for hire.

The don gave Keller a villa and a woman to heal his wounds. Then, when Keller was rested, he gave him work. With his northern European looks and SAS training, Keller was able to fulfill contracts that were beyond the capabilities of Orsati’s Corsican-born assassins, the taddunaghiu. Posing as an executive for Orsati’s small olive oil company, Keller roamed Western Europe for the better part of twenty-five years, killing at the don’s behest. They accepted him as one of their own, the Corsicans, and he repaid their generosity by adopting their ways. He dressed as a Corsican, ate and drank as a Corsican, and viewed the rest of the world with a Corsican’s fatalistic disdain. He even wore a Corsican talisman around his neck—a lump of red coral in the shape of a hand—to ward off the evil eye. Now, at long last, he had come home, to an ancient fortress of gray stone overlooking a cold granite sea. They were going to teach him to be a proper British spy. But first he would have to learn how to be an Englishman again.

The other members of Keller’s intake were more in keeping with MI6’s traditional tastes—white, male, and members of the middle or privileged classes. Moreover, all were recent graduates of either Oxford or Cambridge. All but Thomas Finch, who had attended the London School of Economics and worked as an investment banker in the City before finally submitting to MI6’s repeated advances. Finch spoke Chinese fluently and thought himself especially clever. During their first session he had complained, only partially in jest, that he was taking a substantial cut in pay for the honor of serving his country. Keller could have made the same boast, but had the good sense not to. He told his fellow recruits he had worked in the retail food business and that in his spare time he enjoyed mountaineering, both of which happened to be true. As for his age—he was by far the oldest of the lot, perhaps the oldest recruit ever—he claimed to be something of a late bloomer, which was not at all the case.

The course was known formally as the IONEC, the Intelligence Officers New Entry Course. Its purpose was to prepare a recruit for an entry-level job at Vauxhall Cross, though additional training would be necessary before he would be ready to operate in the field, lest he do irreparable harm to his country’s interests or his own career. There were two primary instructors—Andy Mayhew, big, ginger, garrulous, and Tony Quill, a whippet-thin former agent-runner who, it was said, could charm the habit off a nun and steal her rosary when she wasn’t looking. Vauxhall Cross had scoured the records of both men to determine whether, in their previous lives, they might have encountered an SAS operative named Christopher Keller. They had not. Mayhew was largely a headquarters man. Quill was Iron Curtain and Middle East. Neither had ever set foot in Northern Ireland.

The first portion of the course dealt with MI6 itself—its history, its successes, its stunning failures, its structure. It was far smaller than its American and Russian counterparts but punched above its weight, as Quill was fond of saying, thanks to the native cunning and natural deceptiveness of those who ran it. Whereas the Americans depended on technology, MI6 specialized in human intelligence, and its officers were regarded as the finest recruiters and runners of agents in the business. The hard work of convincing men and women to betray their countries or organizations was carried out by the IB, the intelligence branch. Approximately three hundred and fifty officers were assigned to it; most worked in British embassies around the world, under the safety of diplomatic cover. Another eight hundred or so worked in the general services division. GS officers specialized in technical matters or held administrative positions in MI6’s various geographic controllerates. Each controllerate was headed by a controller who reported to the chief. Though Mayhew and Quill did not know it, “C” had already determined that the recruit known as Peter Marlowe would not be working in any of the existing controllerates. He would be a controllerate unto himself. A controllerate of one.

Having poured the institutional concrete, Mayhew and Quill turned their attention to the tradecraft of human intelligence—the maintenance of proper cover, detecting and shaking surveillance, secret writing, dead drops, brush contacts, memory drills. For a spy’s memory, said Quill, was his only friend in the world. And then, of course, there were the long and detailed lectures on how to spot and then successfully recruit human sources of intelligence. Keller had an unfair advantage over his classmates; he had recruited and run agents in a place where one small misstep would result in an atrocious death. In fact, he was quite certain he could have taught Mayhew and Quill a thing or two about conducting a clandestine meeting in such a way that both agent and officer survived the encounter. Instead, in the classrooms of the main wing, he adopted the demeanor of a quiet and attentive pupil, eager to learn but not to ingratiate or impress. He left that to Finch and to Baker, a literature student from Oxford who was already making notes for his first spy novel. Keller spoke only when spoken to and never once raised his hand or volunteered an answer. He was as invisible as a man could be in a cramped classroom of twelve students. But then that was his special talent—making himself invisible to those around him.