Until now, there had been no breakthrough in heating plasma to a ‘self-sustained burn’ – that is to say, to the point where the plasma generated more heat than was put into it, although there had been many experiments using exotic metals, super-conducting magnets, giant lasers and so forth.

Always, the instabilities got in the way.

In the south of France, the world’s most advanced nations had chosen to build a big expensive reactor costing $25 billion. But this wouldn’t be tested for another eight years. Even then, ITER could very well fail like the Zeppelin, or like the fission breeder reactor in America, fifteen years in the making, and closed down before it had conducted a single experiment.

Other than in a hydrogen bomb, which needed to be triggered by a fissile atomic explosion, the most successful attempt to replicate fusion peacefully on earth had been at the Culham laboratory outside Oxford: here, in 1997, in a gigantic machine the size of the Pompidou Centre, fusion had been achieved – if for less than a second. The trick was to keep fusion going for much longer, and on a vastly smaller scale, but this had eluded the world’s scientific community. Cold fusion, tokamaks, stellarators, magnetic confinement – each had held up a flickering promise. Not one device had proved to work. A self-sustained burn continued to stay out of reach, a chimera.

‘That is, until 7.32 p.m. last Friday.’

But Marvar was rushing ahead of himself. None of this would make sense unless Dyer understood the nature of his research.

‘Pauli? You have heard of him?’

Dyer admitted that he hadn’t.

‘Pauli was a pioneer of quantum physics,’ Marvar went on, with an erudite smile. ‘He was watching a revue at a theatre in Copenhagen when the exclusion principle came to him.’

Marvar had his brainwave after going to see Samir play at Summer Fields.

‘Do you know what gave me the idea?’ Marvar said, gathering momentum. ‘The football!’

In order to make the ‘burn’, you needed to squash atoms into incredibly high densities. ‘The problem is, it’s like wrapping your fingers around a party balloon and then trying to squeeze. The balloon squishes out between your fingers and you can’t do it.’ The only way of attaining fusion was to create an absolutely symmetrical profile. ‘We have never achieved coherence all the way round, that is to say a perfect spherical wavefront – like a wave arriving along the beach at the same time.’ At Livermore, where billions of dollars had been spent on this, an array of long multiple lasers each one the size of two football pitches were beamed onto a target pellet so minuscule that you almost couldn’t see it, and every single time there had been spots.

‘Spots means squishing. It means it is not symmetrical.’