It wasn’t an exaggeration: he would often walk down the street, or watch a group of people in a bus queue, or even at the park, and every single one of them would have a mobile in their hand. Ten years ago, hoiking around a big Nikon with a telephoto lens always attracted attention. Everyone knew what you were doing, straightaway. Or even if they didn’t know, they would make assumptions. People were automatically on their guard; not everyone liked having a lens pointed at them.

But nowadays? No one thought anything of it if you had your phone out – because everyone did. Everyone was doing it, all the time, so no one thought it out of the ordinary.

And that meant you could take pictures of literally anything.

Anything at all.

He put the phone down and sat back on his lounger. Lucy was still ploughing up and down the pool, doing length after length of backstroke. The last time he had seen her in a swimming costume had been at a summer party they’d thrown for Jake’s tenth birthday. She had been a skinny, long-limbed, flat-chested eleven-year-old, running around the garden and jumping through the bright arc of water from a lawn sprinkler. At the age when they were all still totally, wonderfully, blissfully unselfconscious, unaware of the adult world and happy just to play without worrying about who was looking.

But now she looked . . . well, like a different creature entirely, as if she belonged to a different species. The beautiful people were like that. Lucy looked like a woman, and a full-grown woman at that. She was only sixteen but she had curves in all the right places, a tiny waist, legs that went on forever, a chest the bikini top was only just managing to contain. Untouched by cellulite, by age, by wrinkles and lines and all the other stuff that ruined women in the end.

She looked like a character from one of Jake’s graphic novels, DC or Marvel. A young goddess.

But she was a deep one, too. He had observed that much already.

Lucy climbed out of the pool, rivulets of water running off her lemon-yellow bikini. She lifted her face to the sun and smoothed her long hair down her back with both hands. He was pleased to see that in this company – among friends she had known all her short life – she could still be unselfconscious, unguarded. It was good to see. He knew that on her Instagram account she could pout and pose along with the rest of her friends, filtering the image and getting the angle just right to show herself off in the best light. But when she thought no one was watching, she could still be natural. That was a healthy sign from a mental health perspective; there was a lot that troubled him about the deliberate fakery of most social media content.