Strictly speaking, he did not lie to her about his life in England, but he did not tell her everything. She knew about the five wives, she had roared over tales of the rancid apartment in Dorset Square, which she promised to restore to order and cleanliness for him, if only he would give her the chance. But he refrained from an account of his partner and child in Primrose Hill. Darlene wanted to accompany him to England, and he did not want to heighten her interest in the plan by saying no, or complicate his life by saying yes, and settled instead for vague promises. As eighteen months passed, matters took the usual turn. The very sharpest edges of pleasure and novelty were dulled, but slowly, and only slightly, with many restorative backward steps. At the same time, her thoughts turned more frequently to the future, their future together, an awkward subject, for the time must come when the plant would be functioning and he would no longer need to come to Lordsburg, and he would be setting up somewhere else in the South-West or scattering iron filings in the ocean to the north of the Galapagos Archipelago, or exploiting his patents around the world. But if this divergence of feeling was a problem, Beard was inclined to do nothing. In their easy intimacy, in the heat and fierce shadows of New Mexico, it was easily shelved. The past had shown him many times that the future would be its own solution.

So it was a delight to see her now, and go over to the grill and fetch her a jumbo portion of spare ribs, potato salad and ketchup and a bucket of beer to match his own, and sit with her amid the sentimental din and woozy pedal guitars of the country music, and hear her news and tell her his own. They sat close and, keeping well clear of the private realm, he gave her the latest from the diminutive ancient kingdom across the ocean, where, according to the latest scandal, the hard-pressed citizenry had been obliged to empty their pockets in taxes so that the ruling class might clean their moats, build servant quarters, buy trouser presses and hire pornographic movies. Now, down the smog-shrouded cobbled alleyways of filthy cities and in pestilential thatched villages, there were dark mutterings of revolt. For her part, she told him about Nicky's return to AA, where she had found Jesus for the fourth time and had been off drugs and drink, though not cigarettes, for twenty-two days and still had her job at the pharmacy, though only just.

When Darlene had finished eating, she laid a heavy arm across his shoulders and kissed his cheek. 'But honey, the main news is you. Lordsburg was on NBC last night and CNN were filming on Main Street yesterday right by the Exxon station, and everyone's talking about tomorrow. I'm so proud of you!'

She was gazing at him with an expression he had not seen before, a look of smug maternal possession that troubled him faintly. But he did not want the moment, and the grander moment that contained it, spoiled in any way. So he kissed her and they drank another beer and shared a chocolate, fudge and peppermint ice cream. Then they stood and kissed again and hugged, and he told her he would see her in an hour. He had a duty to fulfil.

He made his way across the busy site to the control station, where the whole crew was waiting, crowding in around the consoles to hear him deliver the speech of thanks he had mentally rehearsed on the plane from London. Hammer stood solemnly at his side, arms crossed, like a nightclub bouncer. From somewhere outside came the sound of trumpets and a piccolo, and the thump of a bass drum. The marching band, or some of it, had arrived to rehearse.

The team had wrought wonders, Beard began by saying in the bland tones of group exhortation, in bringing what had first been just a dream, then a stream of frenzied calculations, then an exploration by way of laboratory tests, then a set of drawings, to this, an engineering reality here in the desert. What they had built existed nowhere else in the world except for some related workbench experiments in a handful of competitor labs. But the process of discovery and development was far greater than this single project, magnificent though it was. Water was first split into hydrogen and oxygen in 1789, the principles of the fuel cell first discussed in 1839. Countless biologists and physicists had devoted themselves to the continuing elucidation of photosynthesis. Einstein's photovoltaics and also quantum mechanics had played their parts, and chemistry, the science of new materials, protein synthesis, in fact, virtually the whole of the culture of science had contributed in some manner to the triumph that was now almost theirs. And there was a far larger consideration. Everyone here knew that in the greatest scheme of all, spanning billions of years, the capturing and converting of light and the splitting of water by self-organising living forms had generated atmospheric oxygen and had been the engine of evolution. This had been their inspiration, the process they had attempted to reverse engineer.

Beard filled his lungs, then emptied them with a noisy sigh, and showed his open palms in a gesture of abject modesty.

'This is why I can claim nothing for myself. I stood, like Newton, on the shoulders of giants, hundreds of them, and I borrowed slavishly from nature. By good fortune my Conflation helped me see what others could not, though the door already stood ajar. And what I saw was that the most common element in the universe, hydrogen, could be made cheaply, efficiently and in vast quantities by imitating photosynthesis in a certain way, and that it could power our civilisation, just as this beautiful process has powered life on earth by being its principal biological energy input. So now we will have clean energy, endlessly self-renewing, and we can begin to draw back from the brink of disastrous, self-destructive global warming. Some have claimed that my role was vital, that none of this could have happened without me. Well, who knows? All I say is that I was lucky to have had certain ideas, and I was fortunate to be standing in the right place at the right moment in history, at a time of pressing need. My part was simple inevitability. The point is, we're a team and everyone's part was crucial, every last one of you was a vital link. And truly, it has been my great privilege to work with you and come to respect your expertise. And you should know that I owe everything, we all owe everything, to our dear friend here, the human dynamo, Toby Hammer!'

To applause and cheers, Beard clutched at Toby's wrist, scratching the American's skin in the lunge, and wrenched his arm away from his chest and raised it, boxing-ring style.

Unsmiling, Hammer bowed his head to the redoubled cheers. To cries of 'speech, speech!' he declined with pursed lips, and the meeting began to break up.

When there was just a handful left, men who seemed to want to talk to Beard, Hammer shook his head and silently indicated the door to them and after a moment's hesitation they filed out, and the two friends were left alone. Beard sat down at one of the consoles and stared at a screen displaying three graphs with falling curves. They were not identified, but he guessed they showed the regulation of the catalysts.

'What's up, Toby?'

'I'm not sure yet.'

'Still worrying about a warming failure? They're near to breaking the record today down in Orogrande.'

Hammer did not smile. He was leaning against the wall by the door, hands deep in his pockets, staring over Beard's head. Finally he said, 'This guy Barnard called. The lawyer from Albuquerque, acting for Braby and the Centre in England. He's on his way here now. I said I wouldn't see him unless he told me what he wanted. And he did.'

Toby cleared his throat noisily and came away from the door to stand by Beard's side. He put a hand on the Englishman's shoulder.