It took guts for the passengers of United Flight 93 to challenge their hijackers on Sept. 11, 2001, and writer-director Paul Greengrass (Bloody Sunday, The Bourne Supremacy) shows similar nerve in making his movie about their struggle. United 93 is defiantly star-less, defiantly deglamorized, defiantly devoid of Hollywood hero worship – and all the more riveting because of it. The movie manages to acknowledge the courage of the Flight 93 victims without indulging in Harrison Ford-type heroics or stooping to memorial-service melodramatics. Forget about ‘Get off my plane!’ – here you can barely make out the infamous ‘Let’s roll.