I want any excuse to come home. My dad is not a spring chicken any more. If anyone says, 'Go buy a postage stamp in London,' I'll go and do it.

Good people can do terrible things, and that's what life is all about, the complexities and grey areas. And often characters aren't written that way in movies, especially characters for women. So you end up being either one thing or the other.

My dad had this philosophy that if you tell children they're beautiful and wonderful then they believe it, and they will be. So I never thought I was unattractive. But I was never one of the girls at school who had lots of boyfriends.

It's very difficult to find the time or the money for people to organize rehearsals for some movies. It staggers me how little preparation often goes into these scenes which are difficult and complicated. You think, "God, it's crazy. I've never met this person before and here I am having to work at how to do a whole performance on the set." It was great to have a few days of just talking to Michael [Caine] and Daniel [Barber] and thinking about the characters and the relationship between them before we started shooting.

You are exposing yourself all the time as an actor. There's the risk of being thought of as bad or boring or unattractive.

I spent a lot of time with a real detective, a lady detective inspector who was the only female detective inspector in the whole of East London. She and I hung out a lot. She showed me what she did and I spent time with her. So, [she was] a lot of the inspiration for the way I dressed and sometimes the dialogue in those interview scenes where we're cross examining and questioning the youths and trying to get a confession out of them.

I already feel a bit annoyed at myself for writing screenplays. It's a bit, I don't know, model-singer-dancer-actress that went to a posh school. There's something too weirdly predictable about it.