Hayley from her class was already in there and they stood together at the counter, picking out sweets. The Opal Fruits, she decided, but she had to wait to pay until Joanna arrived. She glanced towards the door and for a moment she thought she saw something – a blur, a trick of the light, something different, like a shimmer in the hot air. But then it was gone. The doorway was empty. Nobody was there.

She tutted loudly, over a screech of brakes.

‘I always have to wait for my little sister.’

‘Poor you,’ said Hayley.

‘She’s such a cry-baby. It’s boring.’ She said this because it was something she felt she ought to say. You had to look down on your younger siblings, roll your eyes and sneer.

‘I bet,’ said Hayley, companionably.

‘Where is she?’ With a theatrical sigh, Rosie put down her packet of sweets and went to the entrance to look outside. Cars drove by. A woman wearing a sari walked past, all gold and pink and sweet-smelling, and then three boys from the secondary school up the road, jostling against each other with their sharp elbows.

‘Joanna! Joanna, where are you?’

She heard her voice, high and cross, and thought: I sound like my mum in one of her moods.

Hayley stood beside her, chewing noisily on her bubblegum. ‘Where’s she gone, then?’ A pink bubble appeared out of her mouth and she sucked it back in again.

‘She knows she’s supposed to stay with me.’

Rosie ran to the corner where she had last seen Joanna and stared around, squinting. She called again, though her voice was drowned by a lorry. Maybe she had crossed the road, had seen a friend on the other side. It wasn’t likely. She was an obedient little girl. Biddable, their mother called her.

‘Can’t find her?’ Hayley appeared at her side.

‘She’s probably gone home without me,’ said Rosie, aiming at nonchalance, hearing the panic in her tone.