They interviewed us separately, there in the hospital. They took notes in their little black notepads. They were going to take us to the station, but you needed me and they could see I needed your auntie Bridge. They told us to report to Twickenham Police Station at 2 p.m. the following day so that they could take a formal statement. We agreed.

You were awake. You ate a sandwich from the vending machine, drank some water. After a stern lecture on the dangers of misusing barbiturates, they discharged you. It was a little after 10 p.m.

On the way home, in the back seat of the cab, you were OK. You were tired and pale, but you were OK. Your auntie Bridge and me were fragments of ourselves, but we put on brave faces. You told us bits and pieces. I had a million questions; I wanted a full account, second by second, but I knew you were not strong enough yet. There would be time, and at that moment it was a great comfort to me to know that, even though their drugs had caused an involuntary overdose, you had been knocked out for most of your ordeal, and nothing too unthinkable had actually happened. Still, I knew you’d been frightened, and that you’d yet to process what they’d intended to do to you.

So here we are at home. It’s the next morning. The police will have interviewed Emily last night, maybe this morning. They know that some mad late-middle-aged woman tried to kill a teenage girl. But once Emily has pinned her brother’s death on your auntie Bridge, they’ll be here not with their notepads but with sirens and cuffs. Something tells me we won’t actually have to present ourselves at the station. We’ll be taken away in the back of a squad car. Your auntie Bridge will not come back.

But you know none of this yet.

Last night, when we got home, I helped you change into your PJs. Auntie Bridge brought you hot milk with honey, but to our great joy you told us you were starving, that you could murder some toast and peanut butter.

‘Coming up.’ Through her unimaginable turmoil, Auntie Bridge still managed to smile – all either of us wanted to do was make it right, make what were potentially our last hours together as special as they could be, and toast was as good a place as any to start.

I was alone with you in your room. You were sipping your hot milk. The moment was a lull, a kind of peace. The colour was returning to your face, a faint hint of pink beneath your freckles.

‘Are you tired… love?’ I asked. I could not, I realised, say baby girl. Not any more. I wonder now why I ever called you that. You are fifteen years old. You are not a baby.

You shook your head, drained your mug, which I slid onto your bedside table. ‘I don’t know.’

I wondered how much of my conversation with Bridget you’d overheard in the hospital. Did you know I gave you those pills? Would you forgive me when I told you? Would you ever trust me again? I could not wait another second. The weight of it was crushing me.

‘Rosie.’ I took your hand in mine. ‘I need to tell you something. I need to apologise to you.’

‘No, I do,’ you said, tears welling. ‘I lied to you, Mummy. I am so sorry.’ You began to cry. I was crying too. ‘I’ll never lie to you again. I’m so, so sorry, Mummy.’ You pushed yourself to the edge of the bed and threw your arms around me. You sobbed into my neck and I into yours.

‘It’s OK,’ I said. ‘It’s all OK now. But I’m the one who should be sorry.’

‘No, Mummy. If I hadn’t lied, none of this would have happened.’

‘Rosie. Listen to me. You have to listen.’

You sat back on the bed, wiped your cheeks with the back of your hand and gave a deep sniff.

‘I made you ill. I did. Me.’ There was no other way to say it. It was as bald and as shameful and as unforgivable as that.

‘What do you mean?’

‘Last night. I gave you my diazepam. I gave you too many, to knock you out, to make you sleep.’

‘So that’s why I had to go to hospital?’

I nodded, closed my eyes. ‘And when you had your auditions, I gave you other stuff. You weren’t nervous. I mean, you were, but not excessively. There’s nothing wrong with you, my love. It was me. I put… medicine in the Rice Krispie cakes. Laxatives one time, loperamide the other – Imodium. That’s what made you ill. Not nerves. Me.’

I made myself look at you. Your mouth was slack with shock. I couldn’t bear the sight, but it was a sight I deserved. I should look at you, I thought. I should make myself bear it, but I couldn’t. I focused on the wet tissue I was twisting in my lap.

‘Last night I didn’t know you’d already been doped,’ I said. ‘I gave you too much diazepam, I know that, but not enough to make you unconscious. I would never have done that. I just wanted to give you a good night’s sleep. But I shouldn’t have given it to you at all, and I’m so very sorry.’ Words were not – would never be – enough. I was beyond forgiveness. But I would spend the rest of my life asking you for it. ‘I was trying to protect you and, ironically, I did. I foiled Emily’s plans – she was trying to lure you away from me, and if I hadn’t given you that stuff, you would have gone to her and who knows where we’d be now?

‘I mean, I know that’s not the point, that’s not the point at all, and it doesn’t make it right, and I am more sorry than I know how to say. I’m going to get help, and it will never happen again, I promise. It will never happen again.’

After a moment, you took my hand, pulled it towards you like it was a gift, and I had a flash of memory – your father doing that same thing to me. In that moment, I can’t explain it other than to say that I felt him with us – I felt his presence, his light or his soul or whatever you want to call it. He was there with us, my Stan, your daddy.

I met your beautiful blue eyes, the eyes he gave you, with mine.

‘Me and Auntie Bridge will help you,’ you said. ‘That’s the triangle. That’s what we do. We’ll be OK, Mummy. I promise.’

‘I love you,’ I whispered. I could not tell you that whatever the road ahead, it was just the two of us now.

‘I love you more.’

‘So, so wrong.’ I smiled. ‘I love you more.’

‘Bloody hell, it’s like a Sicilian funeral in here.’ Bridget, at the door. You didn’t know that in saving you, she’d killed a man, and what that meant for her, for us. She handed you your toast – an optimistic four slices – and went to sit on the other side of your bed. You grabbed her hand and shook it a moment before letting it drop onto the duvet.

‘I can’t eat all this,’ you said, offering me the plate.

I was hungry too – who knew? I lifted a slice. It was cold. I wondered how long your auntie Bridge had been standing outside the door, not wanting to intrude. So typical of her. I loved you both more in that moment than I could possibly say.

Today, within a couple of hours, they will come. They will come and they will take your auntie away. We have hours, maybe minutes left, but to voice that will ruin what little time we have together.

Please, God, let them see it was self-defence. Please, God, don’t let my sister go to prison. And for now, please, God, let the three of us have this moment of peace.