Ed’s emotional age was nine and he enjoyed gentle teasing if he was in a good mood.

‘Water’s hot, but there’s no pressure,’ Harry yelled to Charlie. ‘I’ll go outside and check the pump.’

Harry stepped out after grabbing a toolbox from the garage and slipping on some work boots. The modest, wooden-framed house was on high ground with a hilly four-acre plot. On a clear day, you could see Las Vegas thirty miles south, but right now all Harry got was a face full of rising sun, and a wave from Vern, his grey-bearded neighbour.

‘Want some fresh milk?’ Vern shouted.

‘Always,’ Harry said brightly as he waved back.

‘Could Charlie pick up the latest anti-virus shots for me and Rosie if she’s going into town?’

‘No problem. She’s got to get mine and Ed’s as well.’ Harry didn’t stop because Vern would talk all day if you let him. ‘I’ve got no hot water. I think it’s the pump.’

‘Let me know if you get stuck with that,’ Vern said. ‘Drop by for tea and cake, if you like.’

‘Will do,’ Harry said, now far enough away that he had to raise his voice. ‘I’ll bring some of my tomatoes over.’

DIY and yakking with the neighbours made Harry feel way older than twenty-one as he made the climb to the solar array, set on a natural slope thirty yards from the house.

He often wondered about an alternative history, where Killer-T didn’t happen and he’d gone to college in New York. But Harry was as happy as he’d ever been.

His parents had offered no stability when he was little. Kirsten had done her best, but was always busy with work and Harry rarely felt like the most important thing in her life. So, while it wasn’t easy living in the desert, he felt as if he properly belonged somewhere for the first time in his life.

He pulled his cell and switched on Bluetooth to connect to the panel’s diagnostic app. Four six-yard-long solar strips provided enough electricity for the house, two cars and a large backup battery. Their water was pumped from an underground well and directly heated by the sun for most of the year.

The energy app told Harry that all four panels were doing their job, and the water in the tubes was near boiling, though the sun had barely risen. The problem had to be the pump that sent pressurised hot water into the house.

It took a hex key to loosen the water pump’s sun-warmed metal cover. The pump worked by spinning a little turbine connected to an electric motor and Harry saw that the drive gears were clogged with sand and grit. After switching the pump off, he blasted the dust with a compressed air cylinder, dripped in some lubrication oil and rolled the gears back and forth to spread it.