A bit off-topic...I noticed that Andrew Scott, at least as Moriarty, does look a lot like the original Master from Doctor Who, Roger Delgado, only younger. Wonder if that was intentional. I think that might be possible, considering that Mark Gatiss is a big fan of the Third Doctor (at whose time Delgado played the Master, who encountered the Doctor a lot back then). The final scene of "His Last Vow", which Gatiss wrote, was even inspired by the final scene of "The Green Death".