The idea of transformation - playing something I'm not - is the bit I enjoy most about acting.

Part of me was fascinated by the idea that I would only get next week's episode a week in advance and wouldn't actually know where I was going with it, until the script landed on my mat. But, part of me wanted to know what was going to happen.

The idea of transformation - playing something I'm not - is the bit I enjoy most about acting.

Rowan Joffe was on top of everything. He knew exactly how he wanted everything to be, right down to the fact when I made those telephone calls, I didn't do it afterwards in a studio. I think that's how he operates. He likes it to be as real and as clear as possible.

I'm sure part of the baggage that I bring having played a lot of villains is also pertinent to the movie [Before I Go To Sleep], because I'm sure people look at me and think, "Oh, I'm not sure I trust him or not."

Interestingly, this character [Doctor Nash] is probably closer to me than somebody like the evil Sir Godfrey in Robin Hood or Lord Blackwood who wants to take over the world in Sherlock Holmes. This is a character that's English, he's based in London, and so it's closer to me than a lot of stuff I've been doing recently.

I have an enormous amount of respect for Nicole Kidman. She's just done so many great movies and she's been out there at the forefront of carrying films and being a movie star. On set, it really pays dividends because when you're performing with her, she knows exactly how to play it. You don't have to compensate for her in any way.