Mrs Carter didn’t bother to raise her head for her youngest daughter either. ‘Good morning, Sara,’ she murmured, but she was counting stitches and did not see the look of complicity that passed between the girls.

The Carter sisters waited to be dismissed. Their mother was a disciple of old-fashioned family values. Their father was the head of the household, its disciplinarian, while Mrs Carter’s role was to support her husband and enforce his strict standards of conduct. She spoke in a flat tone, even when she was angry. Despite this, the girls had learned to read her moods. This morning, the waters were calm.

‘You may go and get dressed,’ she said.

‘Thank you, Pamela,’ said Shannon, and the sisters ran up the stairs, tumbling over themselves like puppies, fear escaping from them like steam from a pressure cooker.

Without the need for discussion, they settled on Sara’s bedroom because it was warmer, closing the door behind them. Sara unloaded her spoils onto the carpet. Two apples – one bruised, one pock-marked with blemishes – and a packet of McVitie’s digestives.

‘Well done,’ said Shannon, grabbing the least damaged apple. Sara didn’t mind. She was less fussy than her sister and ate around the brown patches of rot on her own piece of fruit.

Silence for a few moments.

‘What shall we do after ballet?’ Shannon wrapped her apple core in a tissue and stuffed it in the rubbish bag hidden under Sara’s bed before tearing open the biscuit packet. Crumbs fell down her pyjama top as she crammed one into her mouth.

Sara took her own digestive and nibbled its edges delicately. ‘Go and see Brinley?’

Shannon grinned. ‘Yes! I want to know what she’s wearing tonight.’

‘Are you excited about the disco?’

Shannon shoved in the last of her biscuit and wrapped her arms around her knees, feigning nonchalance. ‘Kit said he’s going to be there.’

Sara mimed exaggerated kissing on the back of her hand. Her older sister nudged her harder than was strictly necessary. ‘Stop that right now, Sara Catherine Carter.’

‘So have you?’

‘Have I what?’

‘Kissed him?’

‘Of course not.’

‘But you want to?’

Shannon’s cheeks were aflame again. She gave the sort of shrug that suggested she didn’t care, when the truth was she cared very much. ‘I suppose so.’

Sara’s eyes widened, and she edged closer to her sister, cross-legged and leaning forward, as if about to hear a story. ‘Are you going to?’

Her sister fixed her with a stare. ‘That’s for me to know and for you to find out.’

‘Girls?’ Their mother’s voice drifted up the stairs. Shannon and Sara froze, listening for her footsteps. ‘Are you nearly ready? We’re leaving in twenty minutes.’

Their eyes met, and both grabbed a couple of extra biscuits before hiding their contraband under the bed and getting dressed for their Saturday morning class.