What happens is some of the characters I've played have voices that are so different from my own, that it would be ridiculous if I would dip in and out of that voice in between takes to ask for a coffee, or something. Or to gossip about whatever was going on.

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.

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?

Hitchcock's got a very interesting voice; it's a very controlled, measured rhythm that's quite slow and, in that sense, also felt quite controlling in its pace. He retained something from his childhood, that London sound, as well as adopting some of the L.A. sounds... All of this helps you create the character.

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

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?'

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.