Isobel broke off and struggled to get her voice under control, and Louisa remembered how her mother had told her about Lorna’s extreme, lifelong jealousy of her younger sister and her many small acts of unkindness. Despite her greater beauty and many talents, a few discerning people had felt sorry for Lorna when she was growing up, because everyone always liked Isobel so much better. Some of her parents’ friends had tried to make allowances for her sharp tongue and manipulative ways, but Lorna hadn’t wanted pity – she had only wanted to be loved, as Isobel was loved, happily and naturally and without effort. She had longed to laugh as easily and joyfully as Isobel seemed to do, but her own inability to find the quirks of life amusing made this a losing struggle.

‘It might have been all right if only she’d just left Ed alone,’ went on Isobel, ‘but she wouldn’t. It was a sort of bullying. She kept trying to set him tasks and make him do things which were quite beyond him, all in order to impress Giles, and we had one or two incidents when she nearly did him serious harm. Then she accused him of doing something he hadn’t actually done. She shook him and screamed at him – Ed, who has always been so gentle and so nervous – and literally frightened him out of his wits. He ran away and went missing. It was a nightmare time.’

Isobel’s grey-green eyes looked dark with misery. She saw again the limp figure of Edward being carried into the house after he had eventually been found. She went on painfully: ‘We’d had such struggles to get Edward, with his autism and his physical disabilities, to the point he’d reached, and then he turned right back in on himself and wouldn’t speak for weeks – his fits started again and we came horrifyingly close to losing him. I felt it was entirely Lorna’s fault and in the end we had to ask her to leave.’ She looked at Louisa. ‘I can’t believe the family bush telegraph didn’t drum some of this through to you. Did you know that Giles was Lorna’s first boyfriend and that they went out together all the time they were at university? They were never actually engaged, though it turned out later that Lorna had always assumed that they’d eventually get married.’

Louisa nodded. ‘I think Mum did tell me something about that,’ she said cautiously, ‘and I knew you’d had a bit of a hiccough a few years ago. Must have been terribly awkward for everyone.’