‘Yeah, well, I’m not sure everyone would agree. Look at the evidence: her freak-out last year was pretty shocking. And now she’s been orchestrating this bullying campaign.’

‘She was bullied herself, Abi. You heard her. And that Sasha can be a little bitch – we both know this. Remember, Beth only tells us half of what’s going on. I’ll bet she’s been putting up with all sorts of jibes about her scoliosis, and about … oh, I don’t know, just the way she looks, the way she acts. She’s nerdy. And nerds always get a hard time in school – I should know.’

‘So, did you ever do something like this?’

‘I did other stuff, I’m sure.’

‘Come on, Mark. No, you didn’t.’

‘All I’m saying is that none of us are angels.’

‘It’s the premeditation that bothers me. I took a look at the social media posts she put up; one of them had details of abortion clinics in the Netherlands and the UK, marked for Sasha’s attention. Where did she even learn about this stuff?’

‘Kids these days – they’re just more clued in than we were. The internet—’

‘Yeah, but a year ago Beth would never have even thought to do something like this. Something happened to her.’

‘You’ve said this before—’

‘Well, isn’t it a fair assumption?’

She remembered the word Siobhan Harte had used to describe Beth: disturbed. She felt it like a stone lodged deep in her stomach.

‘We dropped the ball, Mark. And not for the first time. It makes me wonder what else we haven’t noticed.’

‘What I haven’t noticed, you mean.’

‘Oh God, please.’

She was too tired for his sensitivity, too anxious to tiptoe around issues for the sake of maintaining their domestic peace.

‘What did you mean when you said you were not going to intervene for her – that you’d done enough of that in the past?’ he asked.

‘Did I say that?’ she answered, cautiously.

He waited for more, and her footfall instinctively slowed as her thoughts speeded up, casting around for something to say.

‘It was just the heat of the argument,’ she offered weakly. ‘I don’t know what I meant by it. Nothing, I suppose – just looking to score a point. To wound her. There, I’ve said it. Now tell me what an awful mother I am.’

‘Stop it,’ he said, coldness still there in his voice. ‘You want me to say: “Of course you’re not awful.” It’s just a way of seeking praise or forgiveness or something, and I’m not feeling particularly forgiving, Abi.’

‘I don’t even know why we’re having this argument,’ she declared, before increasing her speed so that she could get ahead of him, get away from him, saying over her shoulder: ‘I should have just gone for a walk on my own.’