The British and American strategy—tracking insurgents by abetting them—seemed to follow a convoluted logic: that of a fighter who, trying to zero in on his opponent, waits for a few good shots to the nose. When Fulton traveled to New York with his handlers, he provided valuable inside information about the IRA’s new tactics. But as each such step offered insight, it demanded another step, and another. The information came at a high price.

In Newry, for instance, not long before Fulton’s trip to New York, a policewoman named Colleen McMurray and her colleague, Paul Slaine, were driving past the canal that runs through the center of town. Across the water, an IRA man triggered a flash unit, and a hidden rocket—called a “doodlebug”—burst from the grill of a car he had planted. It slammed into McMurray’s car, injuring Slaine—he lost both legs in the attack—and killing McMurray on the spot.

As Fulton and I surveyed the bloody plain of his career, he said that McMurray’s death was the only one he truly regretted. I asked why, and his hands traced the universal hourglass symbol for “woman.” It seemed almost as though he didn’t want to say it aloud: he had constructed a moral code as a bomber and spy, some unspoken list of atrocities he refused to commit, and apparently it included killing a woman.

Other people paid a price, too. Consider the case of Eoin Morley, a member of Fulton’s bomb squad. After six years as a low-level IRA man, Morley quit and turned away from the IRA. Maybe he did it for the love of his girlfriend, and for her tiny children from a previous relationship. Maybe he did it because of an intra-IRA dispute. Maybe he did it because he already felt old at twenty-two.

That Easter Sunday night, Morley and his girlfriend put the children to bed and then turned their attention to a sink full of dishes. She washed, he dried. Someone knocked at the door. His girlfriend dried her hands, crossed the room, and opened the door. Two armed, masked men burst past her and grabbed Morley. They dragged him out into the garden and forced him to lie down. One of the masked men—Fulton, sources say—raised a high-powered assault rifle and shot Morley twice. The first bullet entered the back of his left thigh. Automatic rifles tend to rise as they’re fired; the second bullet thumped into Morley’s lower back.

As quickly as they had arrived, the men disappeared.

An ambulance took Morley to the hospital. His mother, Eilish, having gotten word of the incident, arrived soon after. Shootings were a way of life in Northern Ireland, and she expected him to rise from his bed and walk out—just like his relatives, just like his friends, just like Lazarus. But then a nurse burst into the waiting room and said, “Would you come quickly?”

Eilish moved to the door of the surgery theater, but someone stopped her at a red line painted on the floor. She wasn’t sterilized and might infect the patient. Her son lay on a table in the center of the room. A doctor approached and said, “We couldn’t save him. It’s only a matter of minutes.” She suspects now that the doctor kept her behind the line not because of infection but to spare her the sight of her son’s body laid bare, bristling with instruments, tubes, wires.