On the evening of August 13, 1998, a maroon Vauxhall Cavalier, registration number 91 DL 2554, vanished from a housing estate in Carrickmacross, in the Republic of Ireland. It was driven to an isolated farm along the border and fitted with a set of false Northern Ireland plates. Then Quinn fitted it with the bomb: five hundred pounds of fertilizer, a machine-tooled booster rod filled with high explosive, a detonator, a power source hidden in a plastic food container, an arming switch in the glove box. On the morning of Sunday, August 15, he drove the car across the border to Omagh and parked it outside the S.D. Kells department store on Lower Market Street.

      “Obviously,” said Seymour, “Quinn didn’t deliver the bomb alone. There was another man in the Vauxhall, two more in a scout car, and another man who drove the getaway car. They communicated by cellular phone. And we were listening to every word.”

      “The Security Service?”

      “No,” replied Seymour. “Our ability to monitor phone calls didn’t extend beyond the borders of the United Kingdom. The Omagh plot originated in the Irish Republic, so we had to rely on GCHQ to do the eavesdropping for us.”

      The Government Communications Headquarters, or GCHQ, was Britain’s version of the NSA. At 2:20 p.m. it intercepted a call from a man who sounded like Eamon Quinn. He spoke six words: “The bricks are in the wall.” MI5 knew from past experience that the phrase meant the bomb was in place. Twelve minutes later Ulster Television received an anonymous telephone warning: “There’s a bomb, courthouse, Omagh, main street, five hundred pounds, explosion in thirty minutes.” The Royal Ulster Constabulary began evacuating the streets around Omagh’s courthouse and frantically looking for the bomb. What they didn’t realize was that they were looking in the wrong place.

      “The telephone warning was incorrect,” said Gabriel.

      Seymour nodded slowly. “The Vauxhall wasn’t anywhere near the courthouse. It was several hundred yards farther down Lower Market Street. When the RUC began the evacuation, they unwittingly drove people toward the bomb rather than away from it.” Seymour paused, then added, “But that’s exactly what Quinn wanted. He wanted people to die, so he deliberately parked the car in the wrong place. He double-crossed his own organization.”

      At ten minutes past three the bomb detonated. Twenty-nine people were killed, another two hundred were wounded. It was the deadliest act of terrorism in the history of the conflict. So powerful was the revulsion that the Real IRA felt compelled to issue an apology. Somehow, the peace process held. After thirty years of blood and bombs, the people of Northern Ireland had finally had enough.

      “And then the press and the families of the victims started to ask uncomfortable questions,” said Seymour. “How did the Real IRA manage to plant a bomb in the middle of Omagh without the knowledge of the police and the security services? And why were there no arrests?”

      “What did you do?”

      “We did what we always do. We closed ranks, burned our files, and waited for the storm to pass.”

      Seymour rose, carried his glass into the kitchen, and removed the bottle of Gavi from the refrigerator. “Do you have anything stronger than this?”

      “Like what?”

      “Something distilled.”

      “I’d rather drink acetone than distilled spirits.”

      “Acetone with a twist might do the trick about now.” Seymour dumped an inch of wine into his glass and placed the bottle on the counter.

      “What happened to Quinn after Omagh?”

      “Quinn went into private practice. Quinn went international.”

      “What kind of work did he do?”

      “The usual,” replied Seymour. “Security work for the thugs and potentates, bomb-making clinics for the revolutionaries and the religiously deranged. We caught a glimpse of him every now and again, but for the most part he flew beneath our radar. Then the chief of Iranian intelligence invited him to Tehran, at which point King Saul Boulevard entered the picture.”

      Seymour popped the latches on his briefcase, removed a single sheet of paper, and placed it on the coffee table. Gabriel looked at the document and frowned.

      “Another violation of Office protocol.”

      “What’s that?”

      “Carrying a classified Office cable in an insecure briefcase.”

      Gabriel picked up the document and began to read. It stated that Eamon Quinn, former member of the Real IRA, mastermind of the Omagh terrorist outrage, had been retained by Iranian intelligence to develop highly lethal roadside bombs to be used against British and American forces in Iraq. The same Eamon Quinn had performed a similar service for Hezbollah in Lebanon and Hamas in the Gaza Strip. In addition, he had traveled to Yemen, where he had helped al-Qaeda in the Arabian Peninsula construct a small liquid bomb that could be slipped onto an American jetliner. He was, the report said in its concluding paragraph, one of the most dangerous men in the world and needed to be eliminated immediately.

      “You should have taken Uzi up on his offer.”

      “Hindsight is twenty-twenty,” replied Seymour. “But I wouldn’t be so glib. After all, Uzi would have probably given the job to you.”

      Gabriel methodically tore the document to tiny shreds.

      “That’s not good enough,” said Seymour.

      “I’ll burn it later.”

      “Do me a favor, and burn Eamon Quinn while you’re at it.”

      Gabriel was silent for a moment. “My days in the field are over,” he said finally. “I’m a deskman now, Graham, just like you. Besides, Northern Ireland was never my neck of the woods.”

      “Then I suppose we’ll have to find you a partner. Someone who knows the turf. Someone who can pass for a local if need be. Someone who actually knows Eamon Quinn personally.” Seymour paused, then added, “Do you happen to know anyone who fits that description?”

      “No,” said Gabriel pointedly.

      “I do,” replied Seymour. “But there’s one small problem.”

      “What’s that?”

      Seymour smiled and said, “He’s dead.”