During the Nazi occupation of Amsterdam, Otto Frank decides to hide his family, who are Jewish, after his daughter Margot is called to appear for transport to a Nazi labour camp. Miep Gies, Otto Frank's office assistant hides them in the attic above the office. The film tells the true story of Gies' struggle to keep the family hidden and safe, as the Nazis turn Amsterdam upside-down. Based upon Gies' memoirs and Anne Frank's famous diary.