Hitchcock is a big ask. I am playing someone significantly older than me and someone significantly bigger than me. The stuff I find very interesting is why certain physical things have come about. How can he be light on his feet when he is so big? How can his weight vary so much? Where does this rather beautiful voice come from?

I was a fan of Hitchcock, but more importantly than that, he is such an inscrutable man, and a very carefully inscrutable man. He apparently was blank-faced with a calm and controlled presence. I was immediately anxious and thought, 'How am I going to get behind that?'

I work best when a little scared, when there's so much more than the lines to think about.

I'm very fortunate that I get asked to do very different kinds of roles and I realize how much I enjoy that. I enjoy the challenge of transformation. There are actors who play one character, or a certain kind of character, the whole of their lives. I really relish the opportunity to have the challenge to totally transform.

There are far more good actors than there are jobs for them, so it's a big question of luck.

If you ever have the good fortune to meet Tippi Hedren, she's an amazing woman. You can't quite believe she is the age she is.

I get plenty of time to re-engage with the world I'm trying to depict, so I'm not always living in these parallel worlds.