It wasn’t love that set me free. It was dedication. It was PC Lockhart’s sense of duty, the one that made him look into the death of a young woman that nobody was asking him to look into. Until he did that, I was trapped, boundaried by the British Transport Police’s zone of responsibility and by my own ignorance and everybody else’s wrong assumptions about who I was and what had happened to me. Only when that young man refused to accept the official reason for my death could I move beyond that boundary.

It was duty and diligence that released me. Matty wanted to possess me; I wanted to possess Andrew; both our desires were warped and wrong. Love lay in the calm passion PC Lockhart has for his job. Do what you need to do. Even bossy old Inspector Barker believes in duty, admires it in Lockhart. It is a hard lesson to learn, hard for all of us because it isn’t glamorous. It’s grey, and dull, often, and involves getting up in the morning and putting our shoes on and going out of the front door on our way to do what is right. No wonder we resist it. No wonder we would rather have sparkles.

I am still absorbing this information when, summoned by my epiphany, PC Lockhart appears on the top landing and uses the back of his knuckles to rap lightly on the half-open door.

Barker swivels in his chair, saying, ‘Come!’ in a tone of voice that implies annoyance although I can see his face and know he is more than grateful to be interrupted.

Lockhart is holding a file. ‘Sir,’ he says as he comes in, ‘Thomas Warren, want to take a look?’

Barker wrinkles his nose, ‘Not unless I need to.’

‘Right-o …’ Lockhart hesitates and I think, this is the moment, now the Warren file is ready for the Coroner and there are no more investigations on that matter to be done, when Lockhart might go one way or the other on me – after all, he has come up with nothing concrete yet.

And then I remember how, just after I saw Andrew for the first time, in the cafe, the time when I thought he was a suicidal young man who might be my love – how I named him Caleb and whispered Caleb into the woman’s ear as she queued for her ticket and she turned and isn’t it worth a try – for if I can do nothing to avenge my own death, maybe I can do this? A single word, spoken with passion, that’s all it will take to put the thought in his head: he may not hear it, but he will feel it.