The seventh series of the BBC espionage television series Spooks (known as MI-5 in the United States) began broadcasting on 27 October 2008 on BBC One before ending on 8 December 2008 on the same channel, and consists of eight episodes, two fewer than previous series. It follows the actions of Section D, a counter-terrorism division in MI5. The primary storyline involves Sugarhorse, a top secret operation set up by MI5 during the final years of the Cold War, and a mole working for the FSB who intends to leak the operation to the Russians. Peter Firth, Rupert Penry-Jones, Hermione Norris, Richard Armitage, Miranda Raison, Gemma Jones, Hugh Simon and Alex Lanipekun are credited as the main cast. Penry-Jones announced his intention to leave the series in December 2007, while it was later announced Armitage would join. Norris and Raison were both asked back after their characters were left open to return at the end of the last series. In developing the series, the producers wanted to repeat the serialised style from series six, and settled on using the resurgence of Russia as the primary storyline as they felt it was, at the time, subtly threatening the security of the West. The producers also participated in several meetings with the writers to discuss the purpose of Sugarhorse. Filming started in London in March 2008, and finished in August 2008 in Moscow, the first time in series history where Spooks was filmed outside the United Kingdom. The seventh series received healthy ratings, with both BBC One and BBC Three ratings together achieving 6.13 million viewers per episode. The series also attracted critical acclaim, with some reviewers considering it to be the best series of Spooks so far. Both factors allowed the BBC to commission an eighth series of the programme for 2009. The seventh series was released on DVD on 12 October 2009 in the United Kingdom, 30 March 2009 in Australia, and 26 January 2010 in the United States. Episodes Cast The series consists of eight main cast members. Rupert Penry-Jones returned as Adam Carter for the first episode. In December 2007 Penry-Jones announced his intention to leave the series after appearing on the show for four years, because he felt his character had run its course and "getting to the point where I needed to move on," adding he would like to explore other avenues in his career. To