Steven Moffat has revealed via his Twitter page that filming has started for series 6 episode 7. He also noted that it will be the 777th ever episode of Doctor Who since it started back in 1963! Series 6 episode 7 is the final episode of part one of the 2011 series, which will end on an “earth shattering cliffhanger”. Follow Steven Moffat on Twitter here, and us here.