The actor is taking on the lead role of George Smiley in a movie adaptation of the John le Carre novel of the same name.
He said: 'They're in the mind; there are no real car chases, rather it's like a high-stakes chess game with everyone watching how the other person moves.'
Asked what attracted him to the role, he said: 'I've played so many of these big extrovert characters, and it was the prospect of doing something that is so still, so quiet.'
The movie is being directed by Tomas Alfredson and it will open in cinemas in September this year.