Argentinian patriarch Julio Madariaga (Lee J. Cobb) urges his German-born nephew, Heinrich von Hartrott (Karl Boehm), to give up his Nazi allegiance on the brink of World War II, but the request is refused. Madariaga’s debauched grandson, Julio Desnoyers (Glenn Ford), joins the French Resistance, risking his life to fight the Nazis in honor of his grandfather, who died shortly after von Hartrott’s Nazi leanings were exposed. The war brings the cousins together for a final showdown.