Acting was David’s one interest which seemed to have no ulterior motive, and he didn’t encourage Diana to share it with him. Hugh disapproved of that, too, but, even if he’d been a theatre buff, it wouldn’t have discouraged David. Diana more freely admired David on the real stage than she did in the social parts he played, which were so often conspiracies rather than simple pastimes. Diana had no talent for being anyone but herself.

‘Why don’t you ever try out for the lead?’ Diana asked him.

‘Lazy, I guess,’ David said. ‘But the minor parts are more interesting, too. You have to get further into them to stay in them when there’s nothing else to do.’

Diana didn’t know how to do anything without working hard at it. David, with more natural facility, got second-class marks in subjects which bored him. For Diana the only choices were first-class or fail.

‘Skim it,’ David would say, so agile on the surface of things, so quick at picking up clues.

What she had despised him for, his need to be what was expected of him, she grew to admire as an ability she could develop only in conjunction with him, but, as they practised dance steps together or played long volleys of tennis, she knew that what was best for her, the pleasure of being with him, was a rehearsal for David for the spring dance, for the tournament. Alone with him she felt innocent. In public, she came to realize that it was not David but herself who was the fraud. Gradually he was constructing a social self he intended to take on, to play for life, while she only hid herself in it until she could discover the means for escape. Being David’s sister would become as much a confinement as a protection.

The monster David had acted out of his system lay in wait for Diana, so ill-equipped at disguises because she recognized them for what they were. Sometimes she suspected there was no stubborn, unchangeable nature at the centre of David, or perhaps anyone else, that she alone was cursed with desires as unmalleable as they were unacceptable. If a Patricia had pointed a finger at her then, Diana would have felt exposed, as the innocent and inexperienced do to the world’s judgment, rather than outraged as she was when it actually happened.

And relieved, she could now admit, because David had been her only requirement in that world which she’d left so far behind her. Oh, it had been awkward with their mother, who had to know of the rift.

‘You were always so close,’ she protested, of that time Diana came to think of as a brief interlude.