Based on a real-life incident, Kathryn Bigelow's tense film stars Harrison Ford and Liam Neeson as the commander of Russia's first nuclear submarine and his executive officer whose first test voyage ends in disaster when the reactor fails. The only hope is for the crew to repair it at the risk of fatal irradiation. But the two men also have very different political agendas, one of which could trigger global conflict rather than maintain the uneasy truce of the Cold War.