At the top of Saltbox Hill, there’s an oak tree. We used to have picnics there, my mother and me, fingers sticky with blackberries and iced buns, catching crickets in the sun. I run towards it, the only solid presence in a shifting world.

The grown-ups are dead.

My mother is dead.

The Carter sisters are gone.

Even at twelve, I know they won’t be coming back. There’ll be foster carers and social workers, a court case, probably. Prison.

The tears come then, hot and bitter. For everything I’ve lost. For my mother drawing her last, lonely breath while I watched over a woman who deserved to die and my father slept off the drink.

For the empty days ahead.

My head is a mumbled, jumbled-up mess.

I think about Sara and the words she spoke carefully through the bathroom door. She wanted to do it. For her sister, she said. But it’s not right, is it? It’s not.

Lies are a necessary evil sometimes, sweet girl. The last words my mother said to me.

I can only save one of them.

Shannon is my best friend. We’re going to work in the same office and share a flat in London and live together until we’re sixty. We can still do that. We can.

And Sara offered to do it. She wanted to.

I lean against the trunk of the old oak tree and slip my hands into my coat pocket. There’s a small notebook inside that I didn’t put there. It’s covered in gold-coloured fabric and there’s a strawberry sticker on the front. The smell is sweet and artificial.

The remnants of a bloodied handprint on the back of it, smudgy from the dampness.

Shannon must have slipped it into my coat pocket when I left it hanging over the kitchen chair at Hilltop House, after the murders and before the police came.

I open the notebook.

Tonight I’m going to kill my mother and father.

The letters are neat and sloping, and I recognize the handwriting. I should do. I sit next to its owner every day at school.

An electric flash of lightning opens up the sky, followed by an ominous rumble. The rain is coming down now, harder and faster, drumming against the earth, stirring it up. It reminds me of last night and the sound of the rain hitting Hilltop House as I stood in the dark hallway, watching the Carter sisters through the crack in the door.

Sara is hovering over her parents’ bed, a ghost in the moonlight. She opens the drawer of her father’s bedside cabinet, plucks out her rag doll and tucks it under her arm.

Shannon presses a finger to her lips. Sara shakes her head. No. But Shannon stares down at her younger sister until she looks away.