Inspired by a true story, following the heroic lives of a world leader and a brave young man swept up in the horrors of WWII. As the war reaches its climax, Germany begins to doubt the loyalties of the Hungarian leadership - in particular Regent Horthy (Ben Kingsley). The Regent tries to navigate his country between the growing terror of Nazi Germany and the oppressive threat of communist Russia. He is ultimately faced with ceding power to another political party or accepting the execution of his son. As the crisis unfolds, thousands of his citizens are forced underground or put into ghettos. One of them, a young man named Elek (Jonas Armstrong), is separated from his family and determined to find them. Aided by the woman he loves, Hannah (Hannah Tointon), Elek disguises himself as a Nazi SS officer, only to uncover far more than he set out to achieve.