Conan Doyle is amazing in the way he has Watson describe Sherlock’s posture, mood swings, his hand gestures, and so forth in the novels.

I always get self-conscious about what I look like in a film, but less so if I'm a character very far removed from who I am. Then I just worry about the performance, and that's equally an odd experience.

I feel that TV and film feed off each other well. It's more in the perception of the viewer than it is of the actor.

Even the cerebral characters I play seem to have physical quirks. They're all "physically inhabited," for lack off a better expression. For instance, Sherlock Holmes has very particular physical gestures which are drawn out in such detail.

I haven't done period dramas back-to-back, or really anything back-to-back. You get asked to do what you're most recently famed for, so I'm careful of not repeating myself.

I'm interested in art for all. I don't want it to be only the sons and daughters of Tory MPs who get to see my plays.

I've gone up two suit sizes. The character I'm playing, he's strong, I can say that much. I've changed my physique a bit, so that requires eating like a foie gras goose, well beyond your appetite. Providing I don't feel too ill, I then work out two hours a day with a phenomenal trainer. It's the L.A. way.