The heatwave had begun in the middle of June and now, six weeks later, it was still going strong. The neat rows of semi-detached houses in Pemberton Road, the north London street, sweltered beneath the relentless daily bombardment of sun so that when she looked at them, they blurred at the edges. The lush green garden lawns had turned yellow and along the edges of the garden Sophie’s plants had all wilted, a cruel reminder that she kept forgetting to water them. In the corner of the cracked patio, a pile of discarded children’s toys lay in an unruly heap – footballs, tennis racquets, space-hoppers.

Sophie glanced at them and frowned. I should tidy them up, she thought, and put them back in the shed where they belong. Instead, she drained the dregs of her drink and closed her eyes. After a few minutes she opened them again and glanced down at her phone on the grass beside the pool. She had another two hours before she had to pick the children up from school. Should she go back inside and do some work? She’d done none whatsoever today and an all too familiar feeling of guilt was niggling at her. But there was absolutely no breeze and it would be claustrophobically hot in the house. Why were British homes so unprepared for summer? No, she was better off out here. She could bring her laptop outside though, sit under the umbrella and at least fire off a few emails. Yes, in five minutes, she decided.

The sound of a door opening nearby made her start. Sophie raised her head slightly and listened with curiosity as she heard flip-flops slapping across the patio of the house next door. She instinctively glanced at the garden fence, as if she might develop X-ray vision and see through to the other side. A few seconds later she heard the unmistakable pop of a bottle of something fizzy being opened and another set of footsteps joining the first.

‘Christ on a bike, it’s hot,’ a male voice said.

‘Tell me about it,’ a woman replied. ‘Who’d be so stupid as to move house in a heatwave?’

They both laughed. ‘Well, we did it anyway. We’re in.’

‘Thank heavens,’ the woman said. ‘The journey over was hairy though. Remind me never to follow a removal van again. Every time it turned a corner, I imagined your great aunty Vera’s china set being smashed to pieces. And I’ve got a headache. Where are the painkillers?’

The man snorted. ‘They’re packed away somewhere along with the Calpol and Strepsils in any one of boxes one to thirty-two if you want to look for them. Anyway, we’d better get started with the unpacking: we’ve got a lot to do before my parents bring the kids over tomorrow.’

‘In a minute, Jack. Let’s just stand out here with some bubbles and enjoy our new home.’

After that it was silent and Sophie suddenly felt conspicuous, like she was intruding on a private moment. But if she moved, they’d hear her and know that she’d been listening. She stayed as still as she could in the water, too afraid to move or even to breathe. Her skin was beginning to wrinkle, and she felt exposed in her faded, too small spotty bikini, even though she knew that the strangers couldn’t see her. Every second that ticked by was like an hour as she closed her eyes and pretended that she was invisible. Eventually she heard the flip-flops slapping back towards the house and the back door closing, and she finally relaxed.