Give it to the Mullahs and perhaps get Shula back, but risk them weaponising his discovery? Give it to his Australian professor at the Clarendon, but risk it passing into the hands of Iran’s enemies? Did he entrust it to the most respectable body within his field – the European Atomic Energy Community, say? Or did he broadcast it to the world, through Wikileaks or a newspaper? Was the answer ‘everyone’ – or ‘no one’? What if Marvar couldn’t find anybody who was deserving of this information: ‘What if there is no right person?’

Plainly, it was tormenting him, the lack of a solution.

They soon finished the bottle. Dyer opened another. It was a New Zealand sauvignon from the Co-op.

‘Do you want a pizza?’

‘A pizza?’ said Marvar.

‘I can ring for one.’

‘Why not? The last pizza,’ he waved his hand merrily, like a conductor.

‘I hope not,’ said Dyer. He got up and dialled the number from the post-it note on the fridge, ordering a quattro staggione for himself, a margarita for Marvar.

‘Twenty minutes,’ said a foreign-sounding male voice.

He refilled their glasses.

Marvar took another large swallow and stared across the room.

‘Yes, maybe you, J. W. Dyer, can imagine it,’ he said, and swivelled his eyes from the bookshelf back to Dyer, and then to Dyer’s open book on the table. ‘You write a book, you put years into it, your life … and no one publishes it. All that hard work, you don’t have one single reader.’ He drained his glass and took the bottle and poured more wine into it. ‘I had a teacher too. Lovely old woman. Piano. “Music unheard has no value,” she used to say. And it’s true, it’s true.’

Dyer looked at him. ‘Oughtn’t we to see how our sons are getting on?’

‘Yes,’ said Marvar, suppressing a burp, ‘let’s do that.’

Dyer found Silvi’s number and dialled it. ‘Hi, Silvi, John here. I’ve got Rustum with me. That’s right, Samir’s dad. We were wondering how the boys are doing?’

Following a brief conversation with Silvi – they were fine, Gilles had made cheeseburgers, everyone now was in the games room playing Fifa – Dyer was passed on to his son.

Leandro didn’t seem to hear him, gaming no doubt. After extracting from his son the earlier score – 3–1, to Winchester House – Dyer asked: ‘Is Samir there? His dad wants a word.’

He handed his mobile to Marvar.