It’s just coming up to 7 a.m. and the streets are deserted. I sat up through the night, reading and rereading Elspeth’s letter, trying to work out what was going on. It seems she is trapped in some place along with ‘others’ and she is waiting for me to come and collect her. But there is no address on the letter, and it was hand-delivered without an envelope, so I have no way of tracking her down. I’m terrified that she is being held somewhere against her will, but where and by whom?

I push open the door of the police station and make my way across the now-familiar reception area to the main desk. An older woman with short grey hair sits behind it. She looks up as I approach. Her face is lined and she has a sour expression that deepens when she sees me. It is then, when I look down, that I see I am still in my pyjamas. I’d flung my coat over them and pulled on some trainers in my rush to get out of the house this morning. Still, I don’t care, I just want to find out what’s happened to Elspeth.

‘Hello, can I help you?’ says the woman.

‘Er, yes,’ I say, taking the letter out of my coat pocket. ‘I’d like to speak to DS Grayling.’

‘DS Grayling?’

‘Yes,’ I reply.

‘DS Grayling’s not here at the moment,’ she says. ‘Can I be of any help?’

I look at her. She’s wearing a uniform and Grayling isn’t here. I have no choice.

‘This was put through my letter box last night,’ I say, placing the letter on the desk.

The woman takes the letter and reads it. She frowns then looks up at me.

‘Okay,’ she says, sighing. ‘And why is this a police matter?’

‘This letter is from my daughter,’ I say, my chest tightening with anxiety.

‘Right,’ says the woman. ‘And that is a problem because …’

‘It’s a problem because my daughter is dead,’ I say. ‘She was killed in a car accident three months ago.’

The woman’s expression changes. She picks up the letter and reads it again then she picks up the phone.

‘One moment,’ she says. ‘I’ll get one of the officers to come and see you.’

Ten minutes later I’m sitting in a small, stuffy interview room. The officer who ‘came to see me’ is PC Kitson, a short, stocky man in his late thirties. He has made me a cup of tea and is now busy reading the letter for the second time.

‘And you’re sure you didn’t see who delivered it?’ he says, looking up at me from the other side of the table.

‘I’m positive,’ I reply. ‘It was quite late, around nine thirty, and I was seeing my friend out. The letter was lying on the mat in the porch.’