a main character. The idea was originally going to be used in the series finale. However, the producers did not know how to fill in episode two, so the death was moved up. According to Wolstencroft, the inclusion of Helen's death was to give the audience the message that "the world of Spooks isn't the world where the cavalry always arrive, because in reality these people [MI5] do risk their lives on our behalf and they do get into sticky situations with genuinely nasty people." The producers also wanted main characters to die on occasion rather than on a weekly or bi-weekly basis; otherwise it would show MI5 officers as not doing their jobs properly. Although Spooks is a serious show, the writers add occasional humour from the characters. According to Wolstencroft, he felt that anybody who works in such an occupation with high responsibilities tends to have humour around, and that those people make jokes even though they have seen "heinous things". This became the basis for creating Jools Siviter. The first series of Spooks saw various storylines involving the main characters. Among these were Danny's obsession with money and spending, by hacking into a credit card database to fool it to give him a better credit rating, and the discovery that Tessa is running phantom agents to pocket their money. Those storylines were intended by Brenton and Wolstencroft to show the audience that the MI5 officers are tempted by money. A principle story arc is Tom dealing with the complexities of his relationship with Ellie, who at first does not know he is a spy. This storyline was based on Mike Baker, whose wife did not know he was a spy for the first six months they were together. As the series progressed, there were more difficulties with the relationship; Brenton wrote Tom's position as if the character did not see the problem. The same episode also introduced the sexual tension between Danny and Zoe. Filming The first series began filming in November 2001, and continued until March 2002. Shooting took place almost entirely in London, with many rural scenes filmed around South East England. Each episode took approximately 12 to 14 days to shoot, although they do not follow on the order of the script; the production crew would film all scenes set at a certain location first, and then move on to the rest. Between 40