 Production began at Leavesden Studios near London, which Warner Brothers had purchased as a permanent studio site.WB had been renting space there for its production of the "Harry Potter" films, but had been leaving the sets up permanently for nearly a decade and eventually chose to make the site semi-permanent.The parts with Tom Cruise in the opening scene were filmed in Liman's editing room, with the actor doing his own make-up and hair, leading the director to say it "may be the most independent thing I've ever done."