“Because the sea weed.”

Jess’s hand shoots up over her mouth, her eyes widening with delight that her dad has told her a joke her mum probably wouldn’t approve of. She commits it to memory, ready to share with her classmates tomorrow.

“Come on, petal. Time to dry that hair and get you to bed.”

He bundles the towel around her so that her body is cocooned in thick cotton, picks her up as if she were a baby, and carries her toward her bedroom, where her mum will blow-dry her hair and put her to bed.

Jess nuzzles against her father’s neck, her nose filling with the familiar smell of grown-up offices, salted peanuts, and the last residue of aftershave her dad puts on every morning. On the short walk from the bathroom to her bedroom, she burrows into his shoulder and thinks—as she so often does—that when she’s older she is going to live in the house next door so that she can always stay close to her mum and dad.

Jess blinked and shook her head, conscious that she was staring at the driver in the next car. As he turned toward her and smiled she saw that his eyes were too deep-set, his chin too large, his lips too full. Jess turned away, her cheeks hot, as though that man must know she did this all the time: that she was always seeing traces of her dad where there were none.

The traffic began to move and Jess eased her foot off the brake. Overtaking the car in front, she swerved into the outside lane and put her foot down hard on the accelerator, only slowing down each time a yellow speed camera loomed into view. When she finally pulled up outside the Notting Hill address her mum had given her, a sign informed her that it was residents’ parking until 10:00 p.m. Jess peered up and down the street but could see neither meters nor traffic wardens. She wouldn’t be more than a couple of minutes anyway.

Pulling down the sun visor, Jess looked at herself in the mirror, running a finger across her eyelid where the remnants of that morning’s eyeliner had collected into small, soot-like particles. She turned her head sideways, studied her long nose—the one part of her body that made her understand why rich people resorted to plastic surgery—and practiced smiling at herself, wondering if it was true that you could alter your mood just by changing your expression. But the smile reflecting back at her was like a window onto the past through which Jess didn’t want to look.

It was her sister’s smile, always had been. For years, when she was little, Jess had taken such pride in her smile being a facsimile of her sister’s. She had loved how strangers’ heads had turned in the street to stare at the similarity between them, how she had felt the world to be a less frightening place with her sister by her side. And then, one day, the resemblance had disappeared, as though a wizard had slunk in during the night and cast a spell over them both. Jess had known—even then—that it hadn’t really been that swift, that the change had occurred over days, weeks, months. But to her it had felt sudden, abrupt. Now she had no idea if she and her sister would still look similar if they stood side by side, no longer knew if strangers’ heads would turn if they walked down the street together.