Spooks (series 1)
Kudos Film and Television developed "Spooks" after releasing Channel 4 medical drama "Psychos" in 1999, though the company initially faced friction from television networks which saw no potential in a post-Cold War spy show. The producers later successfully pitched the series to the BBC after the networks' commissioning teams were replaced. Four episodes were being written when the September 11 attacks took place, and the some scenes were rewritten to take the event into account to show the audience "Spooks's" goal of fighting terrorism. Throughout production, the producers were advised by former intelligence officers from the Security Service, KGB and Central Intelligence Agency. Filming took place from November 2001 to March 2002.
Spooks (series 3)
In producing the third series, the goal was to "raise the bar" higher to satisfy and surprise the audience. The second series finale "Smoke and Mirrors" ended on a cliffhanger which left Tom's fate open. The producers were unsure whether Macfadyen would return at the time they began storylining. Brenton had already written the first two episodes as if he was not coming back. When Macfadyen announced his return for those episodes, they had to be rewritten. Brenton went through a "nightmare" rewriting the first episode as he "dug this enormous hole, and [he] had no idea how to get out of it." It became a long process of growing the story where Tom turns the tables against Joyce. To make a suitable send off to the character, Brenton did not want Tom to be disillusioned; instead he wanted him to "sort of [become] a human being," as there have been real life instances where spies are attracted to the idea that "the world's a stage to them all the time," but later on they start to unravel.