And, of course, Rashid, the Engineer, did not know that a traitor who had been assigned as a guard to an inner perimeter of an Iranian Revolutionary Guard Corps camp on the road south from Ahvaz, was now in flight, and faced – if again in the custody of al-Quds – either stoning to death or strangulation at the end of a rope. Perhaps Rashid, the Engineer, had seen this guard as his Mercedes swept him through the gates of the compound; perhaps the man had swung them open and saluted. Rashid did not know that the man had denounced him because death faced him in his own country: his crime had been to defile a commander’s daughter – the girl had been a willing party but now cried rape.

The man said, ‘I can tell you about the Engineer who made the bombs that killed so many of your soldiers, in Maysan and Basra Provinces, and many Americans. I can tell you who he is and where he is from, and where is the camp that he uses for the building of the bombs.’

And he was left in the bare interview room, with a well-muscled security guard, while the intelligence officer composed the signal to London that would ask whether such information was indeed sufficient currency for a promise of asylum – only a promise, of course… And Rashid, the Engineer, knew nothing of this.

It was fifty-one days ago – two years and six weeks after a sneeze – that the defining moment had been reached. Sarah did not have a photograph of the features of the bomb-maker to fasten to the wall on his right; instead a black outline of a head and shoulders was superimposed on a white background with a name: rashid armajanrashid armajan. The moment, savoured with strong coffee, had provided confirmation that the DNA sample extracted from the abandoned workings of an explosive formed projectile matched that of a target identified by a ‘walk-in’ at diplomatic premises on the Gulf.