The two men took coffee together at the start of the day. Progress and delays were listed and Beard noted whatever was required of him, then toured the site. In an off-the-cuff way he had proposed right at the start that it would be easier to procure more funds if he could claim for the Centre a single eye-catching project that would be comprehensible to the taxpayer and the media. And so the WUDU had been launched, a Wind turbine for Urban Domestic Use, a gizmo the householder could install on his rooftop to generate enough power to make a significant reduction in his electricity bill. On town roofs the wind did not blow smoothly from one direction the way it did on high towers in open country, so the physicists and engineers were asked to research an optimal design for wind-turbine blades in turbulent conditions. Beard had leaned on an old friend at the Royal Aircraft Establishment at Farnborough for access to a wind tunnel, but first there were some intricate maths and aerodynamics to investigate, some sub-branch of chaos theory that he himself had little patience with. His interest in technology was even weaker than his interest in climate science. He had thought it would be a matter of settling the maths for the design, building three or four prototypes and testing them in the tunnel. But more people had to be hired as related issues wormed their way onto the agenda: vibration, noise, cost, height, wind shear, gyroscopic precession, cyclic stress, roof strength, materials, gearing, efficiency, phasing with the grid, planning permissions. What had seemed a simple wheeze had turned into a monster that was eating up all the attention and resources of the half-built Centre. And it was too late to turn back.

Beard preferred to go around alone to witness guiltily the consequences of his casual proposal. By the early summer of 2000 the post-docs each had a small cubicle of their own. Breaking up the group had helped, as had the nameplates on the door, but Beard put it down mostly to his own perceptiveness, the way each of the young men, after seven or eight months, was drifting into focus. He had made a mere half-dozen trips from Reading station in the Prius when, looking up from a speech he was to give that night in Oxford, he realised that, of course, the same driver had picked him up each time. He was one of the two who actually had a ponytail, a tall, thin-faced lad with a mouth overstuffed with large teeth and goofy smile. He came from outside Swaffham in Norfolk, Beard learned in this, his first focused conversation, and had been at Imperial, then Cambridge, then two years at Caltech in Pasadena, and none of these fabled places had diluted the pure inflections of his rural accent and its innocent swerves and dips and persistent rising line, suggestive to Beard of hedgerows and hayricks. His name was Tom Aldous. He told the Chief in that first chat that he had applied to work at the Centre because he thought the planet was in danger, and that his background in particle physics might be of some use, and that when he saw that Beard himself was going to lead the team, Beard of the Beard-Einstein Conflation, he, Tom Aldous, excitedly assumed that the Centre would have as its prime concern solar energy, particularly artificial photosynthesis and what he called nano-solar, about which he was convinced…

‘Solar energy?’ Beard said mildly. He knew perfectly well what was meant, but still, the term had a dubious halo of meaning, an invocation of New Age Druids in robes dancing round Stonehenge at Midsummer’s dusk. He also distrusted anyone who routinely referred to ‘the planet’ as proof of thinking big.

‘Yes!’ Aldous smiled with his many teeth into the rear-view mirror. It would not have occurred to him that the Chief was not an expert in the field. ‘It’s all out there, waiting for us to understand how to use it, and when we do, we’ll be amazed we ever thought of burning coal and oil and the like.’

Beard was intrigued by the way Aldous said ‘loike’. It seemed to mock what he was trying to say. They were going along a four-lane ring road with flowering hawthorns in the central reservation uselessly casting their scent at the passing traffic. The previous night, with no expectation of sleep, he had lain on his bed in his dressing gown reading while she stayed out all night. It was an unpublished bundle of letters to various colleagues from Paul Dirac, a man entirely claimed by science, bereft of small talk and other human skills. At six forty-five, Beard had set down the typescript and had gone to the bathroom to shave. Sunlight was already sloping through the front-garden birch and patterning the marble floor beneath his toes. What a waste, a failure of good governance, to have the sun so high so early in the day. He could not bear to count, he thought as he took his razor to the new sprouting hair between his eyebrows to give himself a younger look, all the hours of daylight he had ever missed in summer. But what could he have done, what was there for any young man at seven in the morning at any time of year, beyond sleep or getting to work? Now his sleep deficit stretched back weeks.

‘Do you think we could ever get by,’ he asked, stifling a yawn, ‘without coal and oil and gas?’

Aldous was taking them at a clip around a giant roundabout as big and busy as a racing circuit, that slung them centrifugally out upon a descending slip road and down onto the motorway, into the redoubled roar of onrushing vehicles, and trucks the size of five terraced houses whining in file towards Bristol at eighty-five miles per hour, and everyone else lining up to shoot past. Exactly so – how long could this go on? Beard, weak and tender from sleeplessness, felt belittled. The M4 demonstrated a passion for existence which he could no longer match. He was for the B-road, a cart track, a footpath. Shrinking inside his Harris tweed jacket, he listened to Tom Aldous, who spoke with the lilting confidence of a prize pupil providing the answers he thinks he knows his teacher wants.

‘Coal and then oil have made us, but now we know, burning the stuff will ruin us. We need a different fuel or we fail, we sink. It’s about another industrial revolution. And there’s no way round it, the future is electricity and hydrogen, the only two energy carriers we know that are clean at the point of use.’

‘So, more nuclear power.’

The boy took his eyes off the road to lock with Beard’s in the mirror – but for too long, and the older man, tensing on the back seat, looked away to encourage the driver’s gaze back on the mayhem outside.

‘Dirty, dangerous, expensive. But you know, we’ve already got a nuclear power station up and running with a great safety record making clean energy converting hydrogen to helium at no cost, nicely situated ninety-three million miles away. You know what I always think, Professor Beard? If an alien arrived on earth and saw all this sunlight, he’d be amazed to hear that we think we’ve got an energy problem. Photovoltaics! I read Einstein on it, I read you. The Conflation is brilliant. And God’s greatest gift to us is surely this, that a photon striking a semiconductor releases an electron. The laws of physics are so benign, so generous. And get this. There’s a guy in a forest in the rain and he’s dying of thirst. He has an axe and he starts cutting down the trees to drink the sap. A mouthful in each tree. All around him is a wasteland, no wildlife, and he knows that thanks to him the forest is disappearing fast. So why doesn’t he just open his mouth and drink the rain? Because he’s brilliant at chopping down trees, he’s always done things this way, and he thinks that people who advocate rain-drinking are weird. That rain is our sunlight, Professor Beard. It drenches our planet, drives our climate and its life. A sweet rain of photons, and all we have to do is hold out our cups! D’you know, I read this guy saying somewhere that less than an hour’s worth of all the sunlight falling on the earth would satisfy the whole world’s needs for a year.’