It's hard for it to make a mark in this city because London has so much culture to offer.

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?

There are things that I would avoid, so I have the choice to say no, when I feel I'm repeating myself too much. But then there could be a reason to do that with a good director. So I think actors have to have a loose philosophy.

You're playing a character in a drama who happens to be based on someone who existed. It's never going to 'be' that person, but it's based on someone well-known, and you want to create enough of that person for it not to be a distraction.

I teach for the Book Trust, which promotes reading and writing with children.

I went to meet Joe Johnston, the director, and he's charming. I've been very lucky. Most of the directors I've worked with are charming. But Joe's a particularly charming man, and he showed me lots of designs and, rather memorably, welcomed me to the Marvel Universe.

I've got to tell you, I've played real characters before and people always bring up this word 'impersonation,' and I'm never entirely sure what it means.