I haul myself up and step towards it. As I do my heel catches something on the floor. It skids away from me, spinning across the tiles towards the sinks. It makes a low clunking sound as it hits the wall and then lies still. I inch my way forward and peer under the sinks.

A knife.

I don’t scream. I don’t drop to my knees. And I don’t run towards the door beyond the sinks.

I stand up.

I know where I am now. I know what’s happening.

I’m dreaming. I’m asleep on the sofa at home and I’m looking for Billy. As soon as I find him the dream will end and I’ll wake up. I step towards the nearest cubicle, one hand outstretched and push at the door, hard. The lock clatters against the wall as it swings open.

Empty.

Of course. Billy’s never in the first place I look for him. I always have to search. I take three steps to my right and push at the second door.

Empty.

‘Mum?’

I spin round, but the pale-skinned person staring back at me from the mirror above the sink has my eyes, not Billy’s. I put a hand to my forehead and stroke the hair out of my face. Four smudged and bloodied fingerprints appear on my skin. A guilt dream. A nightmare in which I discover that I was responsible for Billy’s disappearance.

I crouch down and reach for the knife under the sink. It’s one of my kitchen knives. The handle is smeared in blood. I don’t touch it. Instead I open my handbag, slung across my body, and pull out a tissue. I wrap it around the knife, tuck it carefully into my bag and then wash my hands. Blood swirls around the basin before disappearing down the plughole.

Billy is not here. I have to keep looking.

The second I step out of the door and into the light two figures rush towards me. A man and a woman; their faces are taut with worry. The woman has a phone pressed to her ear.

‘Oh my God.’ The man reaches me first and draws to a halt. ‘What happened?’

The woman puffs towards us, still talking into her phone, her breath coming in short sharp bursts. ‘I can see her … she’s right in front of me … she’s on her feet … she doesn’t appear to be hurt …’

‘Are you okay?’ the man asks.

His fingers graze my arm and I snatch it away from him, smacking my hand against the door frame.

A sharp pain shoots up my wrist and I hug it to my chest. I try to speak but the words feel jumbled in my mouth as my legs give way beneath me.