It's always good to have a world that people don't know about - a world that hasn't yet been done. It's like treading on fresh snow. You're the first one there.

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.

[2015] it's a time that there's a clash of ideologies, similar to the Cold War. I think that a story like this has been waiting to be told, and I think it's a fresh look at the whole earth-shattering business of the collapse of the Soviet Union.

I like to create a character where you believe, deep down, that they don't really care if they live or die. That's very liberating for the character because, if the character is prepared to die, then they can do anything. It's impossible to stop them.

Obviously, television is a writer's medium, so you get a lot more power and authority. With a film, the discipline is having a beginning, middle and end, and having it work in a specific space of time.

I wouldn't put myself in that bracket, but it's one of those things. I think what helps is that we [with Tom Hardey] don't socialize, we don't really know each other, we purely work together.

I'm not suggesting that ours [series] is unique in that, but they can begin to have that depth, that gravity, they can spend some time, so it's a bit more like reading a good novel, if you like.