Dyer would not have become a journalist if he had trusted people. He had been trained not to believe, it was a requirement. People lie the whole time, most of all to themselves. Thirty years in Brazil had taught him to approach Marvar’s story with caution.

Obscure to Dyer was who ‘they’ were. His knowledge of Iranian politics came from what he read in the news. Was Marvar referring to the Iranian Atomic Energy Organisation? To his university faculty in Tehran? To the Revolutionary Guards? Or to a secret faction closer to the Ayatollah?

He lifted the cup to his lips, waiting for Marvar to go on. When he sipped his coffee he felt clear, calm. In Rio that day. He had met her one dry lonely afternoon. She was like the first coffee of the morning. She made things come alive, which is also to make them come true.

It was one of Marvar’s tics, when agitated, to raise his right hand from his sparse beard to the top of his head and pat down his hair until it fell over his eyes.

‘I don’t know what to do … I was going to church to … I feel everywhere I go …’ The rest of the sentence stayed in his mouth.

‘You feel you’re being watched?’ supplied Dyer.

Marvar nodded. He had to clear his throat again.

‘By who?’

‘Cubbage, for one!’ exploding with resentment.

Dyer put down his mug. ‘What, Amy’s father?’

The very same. Ralph Cubbage, of the carroty hair and tailored red jeans, the large black Lexus and Berkeley baseball cap, who in January had been appointed deputy head of Marvar’s department. An Australian professor was nominally in charge, but Cubbage acted as the day-to-day supervisor. From the first morning when he bristled through the Clarendon’s pompous orange-brick entrance, up its wooden staircase and along the corridor to Professor Whitton’s room overlooking the Parks cricket pitch – two long white communal desktops surmounted by eight large screens – Dr Ralph Louis Cubbage Jr. had behaved as though he had an unwarranted claim on Marvar’s work.

‘If he’s not working for the CIA, then – what is your saying? – I’m a Dutch person.’

Cubbage was not alone in his interest. Everywhere Marvar now glanced he saw a wolf-eared shadow. Aside from the Americans and the authorities in Tehran, Marvar seemed particularly fearful of the Israelis, who, between 2009 and 2012, he said, had assassinated seventeen Iranian nuclear scientists. Recently, Marvar’s professor at the Clarendon had received two visitors who purported to be plasma scientists from a lab in Tel Aviv. They gave him a severe inquisition about his work, but were noticeably evasive about their own establishment.

Then, in no particular order, came the Saudis, the Russians, the Chinese, the British, the City, Wall Street, weapons manufacturers, Iranian dissidents – even the oil industry. Marvar muttered, ‘The thing is so big, they would have to be on top of any renewable revolution.’