‘Who would want to be like me?’

‘Everyone. Every young girl. Because you’re what a woman should be, Zoe, clever and sane and kind and self-reliant and – beautiful.’

‘And if that’s true,’ she said lightly, ‘though I disagree, why shouldn’t Lisa become like that?’

‘Because when she’s eighteen she’ll be rich, an heiress. She’ll never have to work for her living or struggle or learn. We’ll live in a house near her mother and she’ll get like her mother, vain and neurotic, living on sleeping pills, spending all her time with spiritualists and getting involved in sick cults. When I look at you I don’t see Lisa’s double. I see her, an alternative she, if you like, thirteen years ahead in time if another path had been marked out for her in life. And at the same time I see you as you’d be if you’d led the sort of life she must and will lead.’

‘You can help her not to lead that life if you love her,’ said Zoe.

And then Lisa’s letters stopped coming. A week went by without a letter. He had resolved, because of what was happening to him, not to see Zoe again. But she lived so near and he thought of her so often that he was unable to resist. He went to her and told a lie that he convinced himself might be the truth. Lisa was too young to have a firm and faithful love for anyone. Her letters had grown cold and had finally ceased to come. Zoe listened to him, to his urgent persuasions, his comparison of his forsaken state with her own, and when he kissed her, she responded at first with doubts, then with an ardour born of her own loneliness. They made love. When, later, he asked her if he might stay the night, she said he could and he did.

After that, he spent every night with her. He hardly went home. When he did he found ten letters waiting for him on the doormat. Lisa and her mother had gone on to some Aegean island – the home of a mystic Mrs Cleasant longed to meet – where the posts were hazardous. He read the childish letters, the ‘darling Peter, I miss you, I’ll never go away again’ with impatience and with guilt, and then he went back to Zoe.

Why did he have to mention those letters to her? He wished he hadn’t. It was for her wisdom and her honesty that he had wanted her, and now those very qualities were striking back at him.

‘When is she coming home?’

‘Next Saturday,’ he said.

‘Peter, I don’t know what you mean to do, leave me and marry her, or leave her and stay with me. But you must tell her about us, whatever you decide.’

‘I can’t do that!’

‘You must. Either way, you must. And if you mean to stay with me, what alternative have you?’

Stay with them both until he was sure, until he knew for certain. ‘You know I can’t be without you, Zoe. But I can’t tell her, not yet. She’s such a child.’