When I was probably about 10 or 11, and I found it was simply something I could do. When you're at school and you do something and you get praised for it, you think, "Oh, right, well I'll do that." From then on, I always thought I'd be a writer. I thought novels at first, and then I sort of naturally drifted into TV.

It was great fun to do because of the central character. With The Girl in the Spider's Web, the girl is really the central character. She's the whole thing.

[The Girl in the Spider's Web] can't be anything other than a sequel, but a couple of books have been skipped, so it is different, in that sense. It's really taking a very strong central character and thinking, how do you execute this? It's quite different.

With any period piece I think the thing to do is forget that it's not contemporary when you're writing and to have the characters feel as much as possible like characters that you would know.

What happened was I was invited to meet Tom [Hardy] to discuss a project that he had in his mind about an adventurer who returns to England from Africa with secrets and with a history, and the original idea was set some 80 years later than it is now. But in the conversation I really took to the idea and I'd wanted for a while to set something in 1830 and 1840 in London, so it struck a chord.

I always thought it would never happen. And then, it became possible. In between commissions, I wrote it as an original screenplay [Allied].

There's more to come. Series 4 [of Peaky Blinders] is coming soon. But I'm proud of making my hometown, which is considered to be completely unfashionable, slightly fashionable. People actually know where it is now.