became much more enthusiastic about the project after learning that Jolie had accepted the role of Fox, saying "the only way they could have got a bigger star to play this role is if they'd hired Tom Cruise in drag." Jolie decided to make Fox seem "distant and unattainable" by having her silent in many scenes. She mentioned Clint Eastwood, who had recently directed her in the film Changeling, as a possible influence for this aspect of her performance. Furthermore, she asked for Fox to get killed, suggesting that "[i]f she was to find out she had killed people unjustly and was a part of something that wasn't fair, then she should take her own life." Common became interested in the role of Gunsmith due to both the script and the prospect of working with McAvoy, Jolie, and Morgan Freeman. Common learned a great deal about firearms as preparation for the role, but said he is not a strong supporter of guns in real life. Konstantin Khabensky, who starred in Bekmambetov's Night Watch, was cast so that the director would have a familiar face around. British television veteran Marc Warren agreed to work in the film because he always wanted to be in a Hollywood blockbuster. Thomas Kretschmann originally intended to pick up the comic series after being cast, but Bekmambetov convinced him not to. Kretschmann said that he undertook "excessive gun training" to "make sure I look good and I look like I know what I'm doing". Kristen Hager originally auditioned for Fox, but accepted the role of Cathy, considering it "fun to play". Filming Location plate shooting took place in Chicago in April 2007. Several chase scenes, including one with a low flying helicopter, were shot in Chicago over two days, on Wacker Drive along the Chicago River, between Columbus Drive and LaSalle Street. The opening scene was filmed using the Carbide & Carbon Building. Production moved to the Czech Republic later in May, scheduled for 12 weeks of shooting, which included a scene in Pernštejn Castle. Using a former sugar factory in Prague, production designer John Myhre constructed a large textile factory as part of an industrial world, the setting of a mythological environment in which looms create fabrics that weavers interpret as assassination orders. Afterward, filming moved to Budapest, then returned to Chicago in August. While the actors performed many of their own stunts, with free