Today’s dinosaurs were the American president on one side, and on the other the fanatical Revolutionary Guards who had arrested Shula and Jamileh, and pledged to incinerate Israel from the face of the earth. Whatever promises they had signed in order to secure the nuclear agreement, Dyer needed to know that for the past forty years these men had sought nuclear weapons. The US president’s belligerent behaviour had prompted the Guards to renew their search. Fusion would give access to a new type of weapon whose limits could not yet be imagined. Marvar’s device – with no great alteration – would grant the Guards an obscene dominion, not merely over Israel, but over the Middle East and beyond. North Korea could supply the rocket. But you wouldn’t need a rocket. You wouldn’t even need high planes bombing. A single bullet would do. A bullet with a capsule in it, containing deuterium-tritium fuel, fired at extremely high velocity. The Empire State Building. The Taj Mahal. Big Ben. The Bodleian. Marvar held up two fingers and pointed at a family of ducks drifting beside the riverbank. Boom boom boom.

Marvar had gone through it all, over and over. He was aware – his last twenty years had trained him – that people would welcome his invention for good reasons and for bad reasons. Then there were those who would not welcome it at all – for the reason that Marvar was Iranian. Two obdurate enemies of fusion were Russia and Saudi Arabia, among the most unstable countries in the world. ‘If someone said: “We now have the technology to change the planet: no more petrol, no more coal, no more gas,” how would Putin treat that? How would the Saudis? The oil cartels would be demented.’

Financiers, investors, hedge-fund managers – they’d all want a share of the knowledge, Marvar said. ‘The cost of world energy is seven trillion dollars per annum. One per cent is seventy billion. If you were to license the process, you’d get more than one per cent. It would dwarf the riches of the richest …’

It was against Marvar’s every dictate to hand over his knowledge to those who would abuse it as they’d abused Shula. At the same time, his heart was full of his wife. Raped, with a mouthful of ants, not knowing what he had done.

Dyer saw it with terrifying clarity. Marvar might get his wife back by telling … But if he told … His dilemma was inflexible. That was why he stood there like a salmon flapping on the bank. Everything in his face, the way he moved his shoulders and ran dismayed hands over his coat, feeling for the answer in the cloth between the buttons, showed his desolation. He was not here. He was somewhere else, in his own cell, alone.