But someone must have suspected. The idea that came to Marvar on the Summer Fields’ touchline excited him so much that it booted all else from his thoughts. When he made the obvious mistake of sending a happy text message to Shula, his fate was sealed.

Word raced back to Tehran, either from the Embassy or else from another source, that Marvar was not being transparent, that he was hiding something. It was too soon to say what they knew, whether they had any inkling of what Marvar had done, but they must have suspected, given their reaction.

Two figures featured prominently in Marvar’s nightmares. A General Damghani in the Revolutionary Guard who had lost his son in a gas attack against Saddam; and above him, an elderly Ayatollah from Qom, cultured, an expert in medieval poetry, who had been tortured by the Savak. This powerful duo were in charge of all Iranian physicists working abroad. They regarded America and Britain – after Israel – in the same light as had Saddam, and they lived by Saddam’s mantra: ‘He who arises to kill you, arise earlier and kill him first.’ Swift to suspect Marvar of betrayal, they called for an urgent new check on his background, and then made a decision. He must be brought into line – before the temptation seized him to share his research with another party.

Marvar’s warning was delivered last Thursday morning to his pigeonhole at the Clarendon. He had inserted the memory stick in his laptop, and found himself listening to a sound recording, no words, merely muffled noises. Less than thirty seconds later, he yanked it out, ran from the room, down the corridor, into the toilet, and vomited.

He said in a flat, used-up voice: ‘You must understand, it’s not hatred they feel. It’s something deeper.’

For the next twenty-four hours, he revolted against his imagination. What he had heard was not true, there was no proof, the recording was a set-up, these were actors, it was too soon for the authorities to have reacted.

Then on Friday he received his cousin’s anguished message. A group of men had turned up early one morning at Marvar’s home off Hessabi Street where Shula was kept under house arrest, and taken her and Jamileh away.

Marvar knew from friends what was likely. He read books, newspapers. It was impossible for him not to reconstruct the scene. To supply, unedited, the images and sounds of that day.

The beating on all the doors, the footsteps on the roof.

Chapter Thirteen