It's an honour to have such a wonderful international cast on board for this world famous murder mystery. Writer Stewart Harcourt has created an exquisite script. His attention to detail is impeccable.

I became fascinated by the fact that people write to give away rather than write to be read. It's the difference between playwrights and novelists.

In The Godfather, for instance, they say they won't deal drugs because they have a code of behaviour. He is the last remnants of that. So playing someone like that, who is also in pain with his kidney stone, means you're beginning to find a dimension of the guy who is king and all show and the private guy who is in pain.

The great exception to that, of course, is Johnny Depp, who is absolutely the ultimate character actor. Johnny Depp is the future of the character actor and thanks to his success maybe we will see the return of an era when my sort of actor is back in vogue. It's not in vogue for me to be in Hollywood movies as lots of different people.

Inevitably, every part an actor plays contains some of himself.

When I was 16, I made some little 35mm documentaries about the poor in London. I went round Notting Hill, which was a real slum in the 1950s, shooting film.

I think we have reached a level in society - with Helen Mirren playing The Queen - when we're not surprised any more. We don't mention names. Yes, it's obvious by inference. But we don't mention names and the film is not up to point fingers at Royalty.