Tamsin sensed that her presence was often stressful for Antonia, because although Antonia knew she had to make conversation she was unable to think of anything to say. And so lately Tamsin had begun to repeat herself, too, returning to the same subjects several times in each visit, sticking to a script she knew Antonia could follow. Certain topics – music, clothes, food – were safe, always guaranteed to prompt a memory that was clearly pleasurable to Antonia, if a little jumbled. Other topics – her past and especially her family – were to be avoided. Any discussion that referenced, however obliquely, Antonia’s parents, was bound to end unhappily, with Tamsin informing a tearful/disbelieving/indignant Antonia that Professor and Mrs Platt had been dead for quite a while. ‘Well, I’d like you to do some asking around, because if that’s so, no one’s thought to inform me,’ Antonia had huffed the last time this subject had, mistakenly, arisen.

‘That’s a very pretty skirt you’re wearing,’ Tamsin said now. Antonia’s clothes were always beautiful: silk shirts and Liberty prints, beautifully tailored jackets and cashmere twinsets.

‘Thank you.’ Antonia looked delighted. She pinched up a bit of the fabric (a sort of rough shot silk) between thumb and forefinger and rubbed it to test the quality. ‘It is nice, isn’t it? I can’t think where it’s come from. It certainly isn’t mine.’

‘Hold on a moment…’ Tamsin stood up and moved round to the back of Antonia’s chair. ‘Antonia – there’s something wrong with your shirt, I’m afraid. I think you’ve got it on back to front.’

‘Have I? Have I really?’

‘Quite impressive, actually,’ said Tamsin, starting to undo the buttons. ‘Must’ve been a real squeeze getting this over your head.’

Halfway down Antonia’s back the shirt’s fabric bulged oddly. It was her bra, also on back to front. When Tamsin removed the shirt, she saw that Antonia had done the clasp up underneath her small breasts, which were being squashed by the bra straps in what looked like an extremely uncomfortable manner.

‘And while we’re at it, we’ll just…’ Tamsin murmured, undoing the clasp of the bra. Unsupported, Antonia’s breasts were slack and low, but their skin was surprisingly smooth. Antonia seemed quite happy for Tamsin to be undressing her. As Tamsin helped her back into her bra, Antonia took a shaky hold of her hand and held it to her chest, pressing her cheek sideways onto Tamsin’s forearm as if it were a pillow. She rubbed her cheek up and down, evidently enjoying the pleasure of this contact with warm young flesh.

‘Mmmmm, aren’t you just lovely,’ she said.