We are at the very last episode of Series 10 and for the Twelfth Doctor (Peter Capaldi), showrunner Steven Moffat. Bill (Pearl Mackie) is no more. Cyber Bill has replaced her And the Doctor is battling two Masters (John Simm & Michelle Gomez). What else can go wrong as The Doctor Falls? Doctor Who: The Doctor Falls airs on BBC One and BBC America on Saturday, 1 July.