We have just filmed the special, which as you may know is set in 1885. I swear to God I couldn’t answer this for laughing for fully five minutes but Steven [Moffat] and I were asked, ‘How can Sherlock Holmes exist in an era without iPhones?’ He just said, ‘There is some history of that’. We are answering all the same questions we were asked five years ago but upside down. Our version has so fundamentally become Sherlock Holmes that people have trouble thinking it could be Victorian.