I squeeze her hand a little tighter. I could leave her blissfully unaware for longer but what good will that do? Our family has lived a lie for over forty years and Bonnie deserves the truth.

‘I don’t know what I’d have done without you all these years,’ she is saying. ‘You know that, don’t you? I don’t tell you as much as I should, but …’

‘I know,’ I say, when she doesn’t finish.

She tilts her head to one side and I can see she’s scrutinising me again. I realise I must be staring. ‘What is it?’ she says finally. ‘What aren’t you telling me?’ She pulls her hand away, clutching hers together in her lap.

I close my eyes and when I open them she’s watching me, waiting, and I know what I need to say goes something like this: Bonnie, you were right. You weren’t Iona’s sister but our parents still did something awful. They bought you when you were a baby, from your mother who lived in the slums. They brought you up like you were their own and you were, you were as much a part of the family as Danny and I have ever been.

Then I picture her face falling in slow motion.

Blood is thicker than water. I can almost hear her words ringing through my ears.

I will lose her. I know that without doubt. If there are no blood ties between us I will lose my sister forever.

And I can’t. I can’t do that. I won’t survive it.

Her eyes trail down my cheeks and I wipe them with my palms.

She leans forward, her face set, and I can see how angry she is. ‘Will you just tell me,’ she says, her eyes flaring wide as her fist slams down on the counter.

‘I know you’ve been drinking again,’ I blurt. ‘I don’t want to go through this again.’ It’s a risky move and there are only little things that make me think she has been, like the strong scent of perfume to mask the smell of alcohol and the fact she didn’t answer when I told her there was nothing stronger to drink.

Bonnie flinches as she sits back, arms crossed in front of her chest, and I know I’m right.

‘That’s it?’ she snaps.

‘Yes. That’s it.’

Can I live with a lie? Do I have the strength Mum did?

‘That’s it,’ I say again, ‘and I’m sorry, but you need to hear this. If you’re not careful you’ll lose Luke and the boys and—’

‘Okay.’ She is holding her hands up. ‘Okay,’ she adds a little more gently. My heart continues to pound, echoing through my ears. ‘I know all that. I know. I just – I’ll get help. Again,’ she says. ‘With everything that’s been going on—’