Marvar had wanted to shout it to everyone! He agreed with Robert Oppenheimer: ‘A scientist cannot hold back progress because of fears of what the world will do with his discovery.’ Even to Dyer’s imperfect understanding, the implications of Marvar’s breakthrough were groundbreaking, although the word did not seem strong enough. Chances were that Marvar, if he was telling the truth, had broken more new ground than Oppenheimer. Not only did fusion matter, it was probably, given the way we were heading, the single thing that mattered. His spherical laser. The sun on earth. What tremendous consequences, in the right humanitarian hands, for our planet. No mining for coal. No fracking for gas. No oil spills. No more pollution. No more global warming … An inexhaustible supply of energy at little cost; all it needed was water. The fabric of world energy would change overnight. Deserts would be irrigated. Places bypassed because previously so dry would become the most fertile. With the assistance of reverse-osmosis water purifiers, the Tigris, the Euphrates, the Sinai would be gardens of Eden, creating food for the world. There was nothing that Marvar’s nuclear ‘football’ might not improve. In the right hands.

But an equal force held Marvar back. What if his discovery got into the wrong hands? This was the prospect that paralysed him.

‘Don’t you want the Clarendon to know what you’ve done?’ said Dyer, not certain how to continue.

‘And have Cubbage pass it to America!’

Marvar didn’t trust the Americans to use the technology peacefully. Dyer mustn’t be lulled by the siren voices of men like Professor Whitton who insisted that fusion was safe. ‘Don’t believe anyone who tells you it’s clean.’ Oppenheimer’s appalled reaction to the H-bomb was the correct one: it was like the plague of Thebes.

Yes, cheap and easy fusion held out the prospect of salvation, but in the same fiery breath it threatened a destruction that had no parallel in history, save for the kind of meteoric explosion that had once gouged out the Mexican Gulf and destroyed the dinosaurs.