I visited the set [of Allied] a few times, and it was a great set to visit. A lot of it was in West London, in an old Gillette factory. You'd go into the factory through the security, and then there were a lot of camels and goats. Most sets are really dull, but this was fantastic.

[Woman Walks Ahead] is from me being a very bizarre child. From the age of about 8 to the age of about 15, I was obsessed with Native Americans.

I'm very, very excited because I'm just completing Episode 6 of Series 4 [of Peaky Blinders], which again I think is the best yet. And I'm loving it and it's not like work, it's not like a labor, I love doing it, and the boys are coming back and they're loving the scripts.

I read more and more and I came across this character, Caroline Weldon. Sometimes in history, you find these people that no one would dare create. They're too mad.

It has to be an actress like Marion Cotillard [in Allied] because there are so many levels to it. It's set in the Second World War, when lots of people were doing things that, outside of a war, you wouldn't do, like killing and dropping bombs. She's doing things that one wouldn't approve of, but it's war.

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.

What I wanted to do [in Allied] was get two characters who fall in love for real, across the barricade, and then it transcends the war.