Cold War, according to Collins. Filming and editing The third series was filmed across five blocks of two episodes, with a director in each block. Filming began in London in January 2004, and took up to 140 days spanning seven months. Each filming day typically lasted eleven hours. Scheduling was often tight throughout the shoot; sometimes the production crew had to "double up" on locations, and the cast often had to learn six pages of dialogue a day. The majority of cameras were handheld, and the filming crew used a variety of lenses, including long-focus lenses, fisheye lenses, and swing and tilt lenses. The first two series was shot with a Fujifilm stock. The third series saw a switch to a new type of Kodak stock, becoming the first television series to use this model. Filming began in the middle of winter, which presented problems for the cast and filming crew. Some scenes were delayed because of bad weather, even snow at one point, and as a result scheduling became tighter. Another problem was the cold temperatures. The beginning scene in "Who Guards the Guards?", where Mace and Khordad meet in Hebron, was filmed on a roof garden in below zero temperatures; however, McInnerny and Paul Bhattacharjee wore summer clothes. To prevent hypothermia a heater was placed near them. The cameras used light-coloured filters to make the environment look warmer. However, winter did have an advantage of longer nights, making night scenes easier; summer nights would last as little as five hours. The producers hired real news presenters from Sky News and the programme London Tonight to present the news of the events from some episodes. All episodes begin with a recap from past episodes, which the producers regard as "an art in themselves" in terms of editing. The opening title sequence went through three changes over the course of the series. More split screen sequences were also added to create more tension for the audience. Overall, each episode took approximately six weeks to prepare, and would take approximately six weeks to edit. Sets and locations Shooting took place almost entirely in London. The directors somewhat followed the filming style of Bharat Nalluri, the director of the first two episodes of series one and two, who used London and the River Thames as characters in themselves. The exterior and interior of Freemasons' Hall continued to be a stand-in for Thames