In Argentina, family man Julio Madariaga (Lee J. Cobb) is the patriarch of his family and considers his farm paradise on Earth. One of his daughters, Dona Luisa Desnoyers (Harriet E. MacGibbon), has married French immigrant Marcelo Desnoyers (Charles Boyer) and they have one son, the playboy Julio (Glenn Ford), and one daughter, the gorgeous student of Sorbonne Chi Chi (Yvette Mimieux). His other daughter, Elena von Hartrott (Kathryn Givney), has married German Karl von Hartrott (Paul Lukas), and they have three sons: Heinrich (Karlheinz Böhm), Gustav (Brian Avery), and Franz (Richard Franchot). In 1938, Heinrich returns from Germany for a family reunion and when he tells that he has joined the S.S., the displeased Julio Madariaga has a heart attack and dies. When France is occupied by the Germans, the family reunites in Paris, and Franz is the Nazi administrator in France. The alienated Julio has a studio where he paints, and has a love affair with Marguerite Laurier (Ingrid Thulin), the wife of newspaper owner Etienne Laurier (Paul Henreid), who is fighting in Belgium. Meanwhile, Chi Chi joins the French resistance and is arrested. Julio uses the influence of his cousin Franz to release her. However, Chi Chi has an argument with Julio for his neutral position. When Chi Chi is tortured to death by the Gestapo, Julio joins the resistance, using his relationship with the Germans to get inside information.