There have always been links between the BBC's Sherlock and Doctor Who, what with the detective drama's co-creators, Steven Moffat and Mark Gatiss, both having also written for the sci-fi show (and in the former's case, being executive producer of it). Moffat even penned a Christmas special last year in which Matt Smith did a turn as Sherlock. Now Gatiss has has revealed that the Sherlock series opener – which is set in the London Underground – was inspired by a 1960s episode of the time-travel series. The Sun reports that Gatiss said: "I am obsessed with the tube and I think it all comes from that story when I was a kid. The first episode of Sherlock is explicitly about the London Underground for exactly that reason – because I love The Web of Fear!" Let's hope there are no complaints about Sherlock going down the tube.