Budapest, 1939. Fearless Krystyna Skarbek persuades a shadowy British handler to send her into Nazi-occupied Poland to gather intelligence and save her mother. Years later, now a battle-hardened agent, she parachutes into southern France to assess the Resistance and greenlight a crucial weapons drop. Going undercover as a teacher, betrayal forces Krystyna to defy orders and take a reckless stand that will define her legacy.