he third series of the British spy drama television series Spooks began broadcasting on 11 October 2004 on BBC One, before ending on 13 December 2004. It consists of ten episodes which continue to follow the actions of Section D, a counter-terrorism division of the British Security Services. It also sees the departure of three principal characters: Tom Quinn is decommissioned in the second episode, Zoe Reynolds is exiled to Chile in the sixth episode, and Danny Hunter is killed in the series finale. In addition to Macfadyen, Hawes and Oyelowo, Peter Firth, Rupert Penry-Jones, Nicola Walker, Hugh Simon, Shauna Macdonald and Rory MacGregor are listed as the main cast.
Though the producers knew that Macfayden would leave the series, they did not know when he would do so, and so the first two episodes were initially written without him. In either case, the producers created a new character, Adam Carter. In addition, the writers heavily researched the episodes; many of the story lines are based on truth. The producers also took information from advisors who were ex-MI5 officers. The series was directed in five blocks of two episodes in each. Filming started in January 2004 and took place over six to seven months. Shooting took place almost entirely in London, England, with some scenes shot in a cross-English Channel ferry in the fifth episode.Overview from themoviedb.org