‘Perhaps,’ said Isobel. ‘But it’s not just a possibility now. Giles and I both know it’s the truth and so do you, but just for the record, Lorna, I do have the scientific proof in case it should ever be needed legally in the future, for whatever reason. But how would you feel about Brooke’s seeing Rory and Giles together?’

Lorna’s large eyes widened suddenly. Isobel thought she looked like a Stubbs painting of a twitchy horse. ‘Iz! That mustn’t happen. Ever. You wouldn’t?’

‘Oh, but I would . . . if I had to. Why shouldn’t I?’

The sisters eyed each other, testing old strengths and weaknesses.

Isobel said: ‘You started this, Lorna, but now that we know Giles is Rory’s father, we both think he should have a say in Rory’s future too. How do you feel about that?’

‘Glad!’ Lorna spat the word out. ‘Glad that there’s a bit of Giles that is still mine and always will be and there’s nothing you can do about it.’

Isobel felt her stomach lurch. Don’t lose your temper, she told herself; don’t get sidetracked into old recriminations. They had been picking at their food without tasting it. Now Isobel gave up the pretence and put her fork down. A vision came into her head of Rory’s piteous face as he’d clung to her and begged her not to send him away. She remembered again the surprise of Amy’s impassioned plea: ‘You can’t send him back to Aunt Lorna, Mum. He’s terrified of her. Think of the effect she had on Ed. Have you forgotten how she practically killed him – how she literally frightened him into one of his fits and he nearly died? How can you be so cruel?’ Amy had said: “Aunt Lorna is a wrecker and she always will be. She’d ruin his life.’

Making an effort to sound calmer than she felt, but conscious that her voice was choked with emotion, she said: ‘So what do you really want me to do, Lorna? If it gives you satisfaction I’ll admit that I find it very painful that Rory is yours and not mine. If you wanted to underline the difference between my son and yours, then you’ve succeeded. But I’ve grown to love Rory for himself and of course Giles loves him too. We’ve talked it over endlessly and I came to offer that we should have Rory at Glendrochatt on a more or less permanent basis – to bring him up for you as Mum was practically doing until she got too ill.’

Lorna said nothing.