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?'

There is this miraculous thing I heard Hugh Grant talking about - the thing about screen acting is that you can read people's thoughts. You are trying to register something inside and usually the eyes in cinema are where you will register that.

When I told people I was going to be doing the movie and the voice of Dobby, they were kind of awestruck, the people who knew about Harry Potter. I felt rather guilty that I didn't really understand the scale of the job I was about to take on. Now, I am well aware of what I'm doing, and actually, it feels a very serious acting responsibility.

There's not a huge pile of scripts at home. It's what happens to be on the table at that moment with your availability. And then you have no control over when these things come out.

There's something in the rhythm and roll of it that is connected to the way Hitchcock thinks and moves. Then there is everything he ingested - the cigar smoking and drinking that's imprinted on his voice.

The prosthetics were interesting because the artist was so good that they could just put a Hitchcock mask on me, but you don't want to do that. You're an actor playing Hitchcock, so it's about how much of that you're going to do.

I know, for a fact, that I'm a very different person on my own than I am with someone else. We are different with each other. These things are constantly adjusted. And that's true of humans. That's not just true of famous people.