Then I remember something. The stones. The gravestones that Geoffrey stumbled upon on a walk, before he had even written the books. He had often said in interviews that the stones seemed to exert a force on him, drawing him in until he could read the names on them – Tom and Cecil. Then he saw the third stone and how the name had been scratched away, and he couldn’t get them out of his mind. He decided to use those names for his ghost boys and came up with a new name and a new identity for the inhabitant of the mysterious third grave. And so Angus’s great love, Iris, was created.

The patch of grass where the stones are laid is accessible via a little pathway to the left of the house. If I judge it right, I can be in and out in under a minute without being seen.

I turn back, my heart hammering in my chest. Any moment now, Bains is going to appear and then it’s all over. But the road is still empty; the occupants of the police cars nowhere to be seen.

Without pausing, I turn left and find myself on a gravel pathway, overgrown with weeds. Only those who really paid attention to Geoffrey and his books would know of this shortcut. It was the focus of one of his lesser-known books, Trouble at Holly Maze House, which was published as a Christmas special in 1997. By then, Geoffrey’s star had begun to wane a little and there was talk in the press that he was having trouble at home himself, though no one was really sure of the details. I know, because after Mum’s death I did as much research into him as I could. After that he disappeared from view for a couple of years, returning in 1999 with a much-celebrated anthology of children’s ghost stories before stepping away from the limelight altogether.

The air feels cooler as I head further down the path, the spindly branches of an elder tree forming a natural canopy above me. The noise of the high street feels a million miles away as I draw closer to the stones.

As I walk towards them more of the story comes back to me.

Angus liked to make model aeroplanes. His desk was covered in bits of cardboard and glue and scissors. He liked logic and patterns, and when he grew up he planned to be an engineer so he could save enough money to leave Holly Maze House and go home. Home was the little terraced house with the blue door in Mallison Street where Angus had lived with his mum and dad. But when his mum died, everything had changed.

In Mallison Street he had been an ordinary kid. One of the things he loved most was playing football in the park across the road – that and eating biscuits with Mrs Perkins, the nice old lady who lived next door.