Was it a struggle keeping your role a secret last year?
“In the last series, there was a lot of fun to be had. I didn’t tell very many people, because that would’ve spoiled it for everybody. People were really surprised. As I say, I was doing a play at the time and the next day [after it aired] this old woman who played a maid came in and she was like, ‘F**k, you’re Moriarty!’”