‘Hello, Anthony,’ he said. ‘Nice to meet you.’

How did he even know who I was? There were lots of people coming in and out of the office and nobody had announced me. Nor had I told him my name.

‘I’m a great admirer of your work,’ he said, in a way that told me he’d never read anything I’d written and that actually he didn’t care if I knew it.

‘Thank you,’ I said.

‘I’ve been hearing about this programme you want to make. It sounds really interesting.’ Was he deliberately being sarcastic? He managed to look bored even as he spoke the words.

I smiled. ‘I’m looking forward to working with you.’

‘It’ll be fun,’ he said.

But it never was.

We spoke on the phone quite often but we also had about half a dozen meetings, mainly at the office or in the courtyard outside J&A (he smoked all the time, sometimes roll-ups but if not, cheap brands like Lambert & Butler or Richmond). I had heard that Hawthorne lived in Essex but I had no idea where. He never talked about himself or his time in the police force and certainly not how it had ended. The production supervisor who had contacted him in the first place told me that he had worked on a number of high-profile murder investigations and had quite a reputation but I couldn’t find anything about him on Google. He clearly had a remarkable mind. Although he made it clear that he was no writer himself and showed no interest at all in the series that I was trying to create, he always came up with exactly the right scenarios before I even asked for them. There’s another example of his work in the opening scenes. William Travers is defending a black kid who has been framed by the police for the theft of a medal which, they claim, they found in the boy’s jacket. But the medal had recently been cleaned and, when the boy’s pockets are examined, there are no traces of sulphamic acid or ammonia – the most common ingredients in silver polish – proving that it couldn’t have been there. All of that was his idea.

I can’t deny that he helped me, and yet I slightly dreaded meeting him. He always got straight down to business with almost no small talk. You’d have thought he would have an opinion about something – the weather, the government, the earthquake in Fukushima, the marriage of Prince William. But he never talked about anything except the matter in hand. He drank coffee (black, two sugars) and he smoked but never ate when he was with me, not so much as a biscuit. And he always wore exactly the same clothes. Quite honestly, I could have been looking at the same photograph of him every time he came in. He was as unchanging as that.

And yet here’s the funny thing. He seemed to know an awful lot about me. I’d been out drinking the night before. My assistant was ill. I’d spent the whole weekend writing. I didn’t need to tell him these things. He told me! I used to wonder if he’d been talking to someone in the office but the information he came up with was completely random and seemed spontaneous. I never quite worked him out.

The biggest mistake I made was to show him the second draft of the script. I usually write about a dozen drafts before an episode is filmed. I get notes from the producer, from the broadcaster (ITV in this case), from my agent – and later on from the director and the star. It’s a collaborative process although one that can sometimes leave me overwhelmed. Won’t the bloody thing ever be right? But it works so long as I feel that the project is moving forward, that each draft is better than the one before. There has to be a certain amount of give and take and there’s some comfort in the fact that, at the end of the day, everyone involved is trying to make the script more effective.

Hawthorne didn’t understand this. He was like a brick wall and once he’d decided that something was wrong, nothing was going to get past him. There was a scene I’d written where my detective meets his senior officer, a chief superintendent. This is shortly after the dead body of the animal rights activist has been found in a remote farmhouse. The CS invites him to sit down and the detective replies, ‘I’ll stand if you don’t mind, sir.’ It was a tiny point. I was just trying to show that my character was a man who had problems with authority, but Hawthorne wouldn’t have any of it.

‘That wouldn’t happen,’ he said, flatly. We were sitting outside a Starbucks – I forget exactly where – with the script on a table between us. As usual, he was wearing a suit and tie. He was smoking his last cigarette, using the empty packet as an ashtray.

‘Why not?’

‘Because if your governor tells you to sit down, you sit down.’

‘He does sit down.’

‘Yeah. But he argues about it first. What’s the fucking point? He just makes himself look stupid.’

Hawthorne swore all the time, by the way. If I was going to replicate his language exactly, I’d be writing the f-word every other line.

I tried to explain. ‘The actors will understand what I’m trying to get at,’ I said. ‘It’s just a detail. It introduces the scene but it’s a key to how the two men relate to each other.’

‘But it’s not true, Tony. It’s a load of cobblers.’

I tried to explain to him that there are many different sorts of truth and that television truth might have very little connection with real life. I argued that our understanding of policemen, doctors, nurses … even criminals is largely inspired by what we see on the screen, not the other way round. But Hawthorne had made up his mind. He had helped me with the script but now that he was reading it he didn’t believe it and so he didn’t like it. We argued about everything, every scene which involved the police. All he saw was the paperwork, the uniforms, the anglepoise lamps. He couldn’t find his way to the story.