the production team had twelve days to shoot each episode. director douglas mackinnon says this was the biggest challenge of the project. the required amount of material was shot for most of the episodes. however, an extra twenty minutes of material was filmed for episode six. director matt lipsey recalls that the team struggled to cut the extra material whilst maintaining the integrity of the episode. lipsey credits moffat for not "being precious" over his material during the editing process. his willingness to cut superfluous material meant that he was taken seriously when he argued for something to be retained.