‘Tony?’ a voice asked.

It certainly wasn’t Spielberg. Very few people call me Tony. To be honest, I don’t like it. I’ve always been Anthony or, to some of my friends, Ant.

‘Yes?’ I said.

‘How are you doing, mate? This is Hawthorne.’

In fact, I’d known who he was before he’d spoken his name. There could be no mistaking those flat vowels, that strangely misplaced accent, part cockney, part northern. Or the word ‘mate’.

‘Mr Hawthorne,’ I said. He had been introduced to me as Daniel but from the very first I had felt uncomfortable using his first name. He never used it himself … in fact I never heard anyone else use it either. ‘It’s nice to hear from you.’

‘Yeah. Yeah.’ He sounded impatient. ‘Look – you got a minute?’

‘I’m sorry? What’s this about?’

‘I was wondering if we could meet. What are you doing this afternoon?’

That, incidentally, was typical of him. He had a sort of myopia whereby the world would arrange itself to his vision of how things should be. He wasn’t asking if I could meet him tomorrow or next week. It had to be immediately, according to his needs. As I’ve explained, I wasn’t doing anything very much that afternoon but I wasn’t going to tell him that. ‘Well, I’m not sure …’ I began.

‘How about three o’clock at that café where we used to go?’

‘J&A?’

‘That’s the one. There’s something I need to ask you. I really would appreciate it.’

J&A was in Clerkenwell, a ten-minute walk from where I lived. If he had wanted me to cross London I might have hesitated, but the truth is I was intrigued. ‘OK,’ I said. ‘Three o’clock.’

‘That’s great, mate. I’ll see you there.’

He rang off. The Tintin script was still on the computer screen in front of me. I closed it down and thought about Hawthorne.

I’d first met him the year before when I was working on a five-part television series which was due to be screened in a few months’ time. It was called Injustice, a legal drama, starring James Purefoy.

Injustice was inspired by one of those perennial questions screenwriters sometimes ask themselves when they’re casting around for a new idea. How can a barrister defend someone when they know they’re guilty? The short answer, incidentally, is that they can’t. If the client confesses to the crime before the trial, the barrister will refuse to represent him … there has to be at least a presumption of innocence. So I came up with a story about an animal rights activist who gleefully confesses to the murder of a child shortly after his barrister – William Travers (Purefoy) – has managed to get him acquitted. As a result, Travers suffers a nervous breakdown and moves to Suffolk. Then, one day, waiting for a train at Ipswich station he happens to see the activist again. A few days later, the activist is himself killed and the question is: was Travers responsible?

The story boiled down to a duel between the barrister and the detective inspector who was investigating him. Travers was a dark character, damaged and quite possibly dangerous, but he was still the hero and the audience had to root for him. So I deliberately set out to create a detective who would be as unpleasant as possible. The audience would find him menacing, borderline racist, chippy and aggressive. I based him on Hawthorne.

To be fair, Hawthorne was none of those things. Well, he wasn’t racist, anyway. He was, however, extremely annoying to the extent that I used to dread my meetings with him. He and I were complete opposites. I just couldn’t make out where he was coming from.

He had been found for me by the production supervisor working on the series. I was told that he’d been a detective inspector with the Metropolitan Police Service in London, working out of the sub-command in Putney. He was a murder specialist with ten years on the force which had come to an abrupt end when he had been kicked out for reasons that weren’t made clear. There are a surprising number of ex-policemen helping production companies make police dramas. They provide the little details that make the story ring true and, to be fair, Hawthorne was very good at the job. He had an instinctive understanding of what I needed and what would work on-screen. I remember one example. In an early scene, when my (fictitious) detective is examining a week-old corpse, the crime scene examiner hands him a tub of Vicks VapoRub to smear under his nose. The mentholatum covers the smell. It was Hawthorne who told me that, and if you watch the scene you’ll see how that moment somehow makes it come alive.

The first time I saw him was at the production office of Eleventh Hour Films, which was the company making the series. Once we got started, I’d be able to contact him at any time of the day to throw questions at him and would then weave the answers into the script. All of this could be done over the telephone. This meeting was really just a formality, to introduce us. When I arrived he was already sitting in the reception area with one leg crossed over the other and his coat folded over his lap. I knew at once that he was the person I had come to meet.

He wasn’t a large man. He didn’t look particularly threatening. But even that single movement, the way he got to his feet, gave me pause for thought. He had the same silken quality as a panther or a leopard, and there was a strange malevolence in his eyes – they were a soft brown – that seemed to challenge, even to threaten, me. He was about forty years old with hair of an indeterminate colour that was cut very short around the ears and was just beginning to turn grey. He was clean-shaven. His skin was pale. I got the feeling that he might have been very handsome as a child but something had happened to him at some time in his life so that, although he still wasn’t ugly, he was curiously unattractive. It was as if he had become a bad photograph of himself. He was smartly dressed in a suit, white shirt and tie, the raincoat now held over his arm. He looked at me with almost exaggerated interest, as if I had somehow surprised him. Even as I came in, I got the feeling that he was emptying me out.