I didn’t need to visit the main setting for ChildMinder. I used to work there.

When I was a trainee psychiatrist, I assessed patients who had been admitted the previous twenty-four hours who had deliberately self harmed. Usually overdoses of paracetamol.

They were admitted to a large Nightingale ward near to the Accident and Emergency department.

I saw them in a side room near to the ward entrance.

It was a small room, with an internal window high up the wall over the door. It was opened and shut with a Victorian pulley system. Even if shut you could hear the sounds of the ward outside.

The room had basic furniture, a desk and two chairs. One night, walking down Middle Meadow Walk coming home from Sandy Bells pub, I looked up at the old hospital, which was now being converted into flats.

I wondered – what if someone gets a flat there and it is haunted by the ghost of a patient who died? Then I thought, what if I bought a flat in the ward I had worked in and one of my patients – a child – had died and came back to haunt me? Instantly, I had my two characters – Joseph Croan, a child psychiatrist and Sam, his child patient. It wasn’t long before they wouldn’t stop talking to me and I discovered my title – Child Minder – ‘mind’ being the Scots word for ‘remember’.