He heard a clock strike midnight, so he reckoned it would be seven o’clock in the evening for Marnie, whether she was in New York or Toronto. She would be expecting a call. He had told her he would ring her as soon as he got back to the flat after dinner and report on the evening, but this was no moment to be asked for explanations. His mobile was switched off, and when he turned it on he saw that he had one missed call. He pressed 121 and listened to Marnie’s voice, teasing but a little anxious too, he thought. ‘Hi there – what a very long supper you’re having! Ring me soon. Have lots to tell you. Love you.’ His heart sank. He decided to text Marnie and try to forestall any conversation with her until the morning. He punched in a brief message saying that something unavoidable and unexpected had cropped up and he would call her tomorrow. He thought she would find it extremely bothering and imagined all her defence mechanisms springing into action as she read it. Thinking of you. Don’t forget I love you, he added, and hoped she would believe him.

Louisa woke in the small hours, and, as Christopher had guessed, the misery of remembering what had happened was almost worse than being told for the first time. But she was touchingly grateful to find him still there.

‘You should go to bed properly now,’ he said.

‘Will you stay with me?’ she asked. ‘I know I ought not to ask it of you but I promise I won’t cause any trouble now.’ She gave him a wobbly little smile. ‘I just don’t think I could bear to be alone tonight and I think Marnie would understand though I promise not to tell her if you’d rather not. Please?’

‘Of course I’ll stay with you,’ he said. ‘Marnie certainly wouldn’t want me to leave you like this. Of course she’ll understand.’ He hoped this was true.

‘You could sleep on the spare room bed,’ she said. ‘I’m afraid it’s not properly made up but there’s a duvet on it.’ She looked at him sadly, knowing he would never now give her the one thing she had thought she wanted from him, but deeply grateful for his presence and support. He followed her up the stairs and she came and kissed him goodnight, and thanked him and clung to him. He held her to him for a minute, fighting an urge to respond to her more fully.

‘Don’t give up, Louisa,’ he said urgently. ‘You’ve beaten this thing before . . . you can do it again. People do make extraordinary recoveries from cancer against all the odds. I know that from my doctor brother-in-law. Anything can happen.’