I spoke to Tom's [Hardy] manager and said, "While we're talking about Taboo, do you mind if I also mention this film project that I've got, which is called Locke, and I need Tom to play the lead." And we spoke about both in that meeting and in the end the deal was that I would do Taboo if he did Locke and vice versa.

It's great that the story [Allied] is set in the '40s because the '40s feel to it is completely appropriate.

I was 21, when I heard the story that inspired this [thriller Allied], and I wasn't even a screenwriter then.

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.

It felt [at the Allied set] like, "At last, I'm in Hollywood," even though I was in West London. It was like, "This is how a film should be made." It was beautiful.

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 think people are drawn to characters that break the rules. I think there is something about a good person doing bad things for what they consider to be a good reason. Then the battle is on to almost prove to the audience that it's justified. How far can you go with that? How far can that character go before people won't accept it? Trying to walk to edge of that line is a challenge.