Trevor Byrne stands up and offers me his seat. I pull it around so that I can be next to her. I try to take her hand, but she won’t let me. Instead she holds herself stiffly, arms folded over her chest, staring furiously at the table, her mouth a hard little bud. How miserable she looks. But underneath the bravado, there is deep fear. I can see it.

‘Beth,’ I say softly. ‘I know you’re frightened. I know what happened today was awful, and that there must be a reason why you did such a thing. If you would only tell us—’

‘Why? Were you shocked?’

I stare at her, like I’ve been slapped. The cut of meanness in her voice. She’s looking at me now, small-eyed, watchful. Taking in my reaction. And I realize that I am frightened of her. That I have been frightened of her for a long time.

‘Of course I was shocked. My God, Beth, you—’

‘I didn’t think you’d be surprised at all.’

My eyes flicker over her, then cut to Mark. We both caught the emphasis. He’s looking at me strangely, I can’t make out the meaning of his stare. I feel the weight of Cassins’ gaze and that of the other detective in the room. Trevor Byrne’s, and all the unseen eyes peering at me from behind the mirrored glass. What a sight we are. What a family tableau.

‘I love you, sweetheart,’ is what I tell her. ‘No matter what you’ve done, you’re still my little girl.’

‘All grown up now, though, aren’t I?’ She tries to smile but it dies on her face, the mask slipping.

‘I thought you loved her,’ I say. ‘I thought you were close. Why?’

She holds my gaze for a moment and shrugs; her eyes fill with tears.

‘They left me behind,’ she says simply. ‘I couldn’t stand it.’

‘But—’

‘She was my friend!’ she blurts out, her voice breaking. ‘Mine! Not Eva’s!’

With that, she withdraws into herself. Her anger shrivels before my eyes. She shrinks around what’s left of it, stares sideways at the wall, says to no one in particular:

‘Are we done here? Can I go now?’

I look at her, amazed.

‘Go? Where do you think you’re going to?’ I bend down, on my knees in front of her, imploring her to look at me, to penetrate the part of her brain that remains shuttered, wilfully apart. ‘Beth, you can’t come home, do you understand that? You can’t come home.’

I start to cry then. Because I know it will be years. Years. She will be grown. She will be a different person. Both our girls, gone.