Portrait of a Spy. Daniel Silva

lost and the network exposes itself. In the earliest years of the conflict against terrorism—when Black September and Carlos the Jackal were running amok, aided by useful leftist Euro-idiots such as the Baader-Meinhof Group and the Red Brigades—intelligence officers mainly used physical surveillance, hard wiretaps, and good old-fashioned detective work to identify the members of a cell. Now, with the advent of the Internet and global satellite communications, the contours of the battlefield had been altered. The Internet had given the terrorists a powerful tool to organize, inspire, and communicate, but it had also provided intelligence services with a means of tracking their every move. Cyberspace was like a forest in winter. The terrorists could hide there for a time, hatching their plots and organizing their forces, but they could not come or go without leaving footprints in the snow. The challenge for the counterterrorism officer was to follow the right set of tracks, for the virtual forest was a dark and confusing place where one could wander aimlessly while innocents died.

      Gabriel and his team cautiously set foot there the next morning when British intelligence, under standing agreement, shared with their American cousins the preliminary results of the inquiry into the Covent Garden bombing. Included in the material were the contents of Farid Khan’s computers at home and work, a printout of every number he had dialed from his mobile phone, and a list of known Islamic extremists he had encountered while he was a member of Hizb ut-Tahrir and al-Muhajiroun. There was also a copy of the suicide tape, along with several hundred still images captured by CCTV during the final months of his life. The last photo showed him standing in Covent Garden, his arms raised above his head, a bloom of fire erupting from the explosives belt around his waist. Lying on the ground a few feet away, shielded by two men, was Gabriel. When the picture was magnified, it was possible to see the shadow of a gun in his left hand.