Beard said, 'Toby, you're a genius!'

Hammer nodded in grave acknowledgement. 'I like to bring things and people together. But, Michael. This is your invention. The genius is you.'

Feeling serene now, Beard nodded in return. This was how friendship should be.

Even as they parked, men in T-shirts and baseball caps, some holding clipboards, were hurrying towards them through a dust cloud. This was Hammer's team, or a part of it, and among the group were engineers, hydraulic and computer specialists and other technicians. Beard had done the theoretical work, designed and supervised the experiments in the lab, but the rest, the scaling up, the drawings, the mass-production design, the actual plant layout and construction, the pipes and valves and how they were represented in the software, was not his concern. He knew the principles, he owned the patents, but he could not have given a detailed account of the site. Here on the open plain, he was an eminence, almost a legend, and everybody treated him with appropriate respect, with the intimate politeness at which Americans excel, but no one needed him to come and peer into a trench or adjudicate on spheres of responsibility. The NREL in Golden, Colorado, had examined the prototype and confirmed that the process he had devised worked to a high level of efficiency. The rest was for this friendly bunch of practical men waiting for Toby Hammer, who himself knew nothing about the technicalities or underlying principles, but had a gift for detail and co-ordination and man-management.

So now, as the two men stepped out of their car and engaged in a round of handshakes and backslaps, Beard prepared to slip away. The roasting air was amplifying the appeal of cooking smells, of meat grilling on wood fires, drifting across the parking lot from the concessions. The news about Tarpin had ruined his brunch, but his concentration would remain unsettled until he had strolled down this instant desert boulevard and made a considered choice. Toby, who kept a pick-up on site, handed the car keys over and he and his group headed across the parking lot towards the array.

After barely five minutes' reflection, Beard was sitting alone in deep shade at a trestle table with a paper plate of barbecued brisket, Texan style, with three giant gherkins and a mound of potato salad and a small waxed-paper bucket of draught beer. By the common standards of energy production, the Lordsburg Artificial Photosynthesis Plant, known as LAPP to the engineers, was negligible, a mere toy, barely a prototype. But sitting here, with the blue smoke of grilled chicken rolling past him from the joint next door, and country rock on speakers mounted on poles, and the chefs shouting cheerily to each other of the news that twenty-four hungry men from the 'Lordsburg!' sign-erection team were heading this way for rump steaks, Beard felt himself to be at the centre of the world. How delicious it was, not only the food, but to be here, cosily ignored, in an obscure corner of the American heartland, and to know that the din, the construction, the digital media and soon, jet fighters and marching bands, this imminent industrial revolution, owed their existence at this spot among the palmillas and dried grasses to what he had once conceived eight years ago, lying on a dirty sofa in a basement flat five thousand miles away.

He had his teeth clamped about the fourth piece of succulent brisket when something happened that he had not experienced since his schooldays and even then considered intensely annoying. He felt a presence at his back and before he could turn, warm hands clamped over his eyes, gripping his head tightly so he could not move, and a voice said in a whisper into his ear, 'Guess who?'

A finger of the left hand was pressing uncomfortably on the northern hemisphere of his eyeball and he dared not struggle. His tongue was laden with meat, and in the shock of the moment he was unable to swallow. But still, he managed to say indistinctly, 'Tarpin?'

'She your Chinese girl?' There was merry laughter as he was released.

Darlene, of course, and his irritation vanished as he struggled to his feet, chewing rapidly to empty his mouth, and embraced her. Who could not love Darlene? She was a good-hearted, overweight woman from Nebraska who had waited tables all her life, had married three times, had four grown-up children who appeared to adore or need her, for they phoned constantly, had discovered New Mexico twelve years back and changed her name from Janet. She now spoke fluent Spanish, after living for six years with a Hispanic truck driver in a trailer on the southern edge of town before she threw him out.

And now she had set her heart on Michael Beard. At their first sexual encounter she had told him he was her very first older man. And then, correcting herself, her first much older man. He did not like to think that her own choices, like his, might be narrowing. He was, after all, something of a local hero, honoured by the Chamber of Commerce on East 2nd Street for bringing jobs to the town. He was not such a bad proposition. And she, of course, fulfilled Beard's old fantasy of the grand lowlife. In that way of Americans good-naturedly declaring a class affiliation, she chewed gum, open-mouthed, remorselessly, all day, even while she talked, stopping only in order to kiss him. She never read books or newspapers or even magazines, had never been to church, and disliked wholesome food as much as Beard, and when she doused her plate was fond of evoking Ronald Reagan's celebrated insight that ketchup was a vegetable. Beard was disappointed by her lack of religion. It did not conform to type. But she was staunch. She was not even an atheist, she said, she could not care enough even to deny God's existence. He simply did not 'come up'.

They had met when Beard, with many hours to kill before a meeting, drove out of Lordsburg one afternoon and turned along a track that led to the ghost town of Shakespeare and, faintly bored, afflicted in the spring warmth by formless sexual expectation, wandered down the old main street, from the old saloon to the old general merchandise to the old Stratford Hotel, where Billy the Kid once washed dishes. As Beard was leaving he came across Darlene in the parking lot. She had come out to lend support to her friend Nicky, who was after a job as a tour guide and had just been told she was too unconfident and ignorant to qualify. She was crying on Darlene's arm as Beard, in predatory mode, strolled across and kindly asked if he could be of help. Darlene explained the outrageous rejection while Nicky tried to join in. She was a scrawny, freckly, crop-haired chain-smoker with a stutter, trying to inhale even as she wept, and Beard thought that he himself would not have hired her in any capacity. But this was her third failed attempt in as many days to get a job and so they went back to Darlene's trailer and drank consolatory beers and scotch all afternoon, with Nicky producing cocaine and pot, which he and Darlene refused. To endear himself to Darlene he promised to find Nicky something out at the site (which he did, and Hammer sacked her two days later), and after she had left to see to her children, Beard and Darlene made love in the oak-veneered bedroom next door.

He saw her whenever he came to Lordsburg. There was a bar on 4th Street they liked, and sometimes they partied in his room at the Holiday Inn, but mostly they enjoyed themselves in the trailer, which she kept neatly. There was a small yard at the rear with two lemon trees she cared for like children, trees just big enough to cast some shade in the late afternoon on a couple settling down to drink. After a couple of scotches – she shared that taste with Beard – she laughed a lot, very loudly, and after three or four drinks she loved to go indoors, into the cool throb and rattle of the air conditioning, to make love. For Beard the affair was an unexpected sexual renaissance, with piercing sensory pleasure, much like that near-inversion of agony he remembered from his twenties. A lifetime had swept by since he last shouted out involuntarily like a madman at the moment of orgasm. He never would have believed he would be experiencing such extremities of sensation with a woman of fifty-one, whose body was as slack and tired and inflated, as scribbled on by varicose veins, as his own. He assumed that this might well be his last throw at such ecstasy, and so he cherished her. Just as he took presents from El Paso or Dallas airports to Melissa and Catriona, so he lugged in reverse items for Darlene from Heathrow. In another town, another country, she might have been considered a noisy drunk. In Lordsburg she was popular and useful, and through her he came to respect the town. Apart from her evening waitressing job at the Lulu Diner, she worked as a volunteer in a grade school, tidying classrooms and cleaning up grazed knees. For two weeks a year she did unpaid menial jobs at a summer camp for autistic kids in the Gila hills. Only rarely, two or three times in a year at most, was she gathered insensate off the sidewalk at night by a neighbour or a patrolman and brought home to the trailer.