twelve to eighteen months after their initial meetings early in 2008. They settled on using Russia, which was facing a resurgence in power after the Cold War, which the producers felt, in subtle ways, would threaten the security of the west. Sometime through the writing process, the producers set up a story-arc, Sugarhorse, to be a threat throughout the series and have it resolved by the finale. The writers enjoyed making the Sugarhorse storyline because it was one of the instances that "really brings Harry to the edge" and causing him to doubt everything he has done or achieved. The writing team took several meetings together to discuss what it is and how it should work into the storyline. Christian Spurrier noted it was "kind of a headache" to figure out how to "weave it in" to the series and work out what parts would be used in which episodes. The producers wanted to use a scene relating to Sugarhorse as the finale scene of every episode it was featured in, as the producers believed it would provide a "right hook" to the audience. Adding the new storyline would allow the series to return to the world of spying, truth, and who the characters should trust. Throughout the writing process, several cast members would give suggestion notes to the writers on how to improve some scenes. The writers were frequently annoyed with Armitage, who gave out more notes than any other cast members, however the writers also liked some of his ideas and included them in the scripts. The producers believed that the seventh series was among the more brutal than the others, citing the violent death of Ben. Filming Filming started in March 2008, and finished in August of the same year. Before principal photography commenced, director Colm McCarthy participated in helicopter shots over London. In each block of episodes, the cast and crew would often film all scenes held in certain locations at once, for instance all scenes set on the Grid, although taking place in different parts of each episodes, would all be filmed together before moving on to another set. However, the cast had trouble following the storylines with this method. A different Director of Photography was hired in each episode. Because of this, the filming style inside the Grid set changed in every episode. To film public shots, a small film crew was used so