The Communist People's Party makes life difficult for mission priests Rev. O'Banion (William Holden) and Rev. Bovard (Clifton Webb) in 1940s China. The cook for their mission, young local Siu Lan (France Nuyen), is in love with O'Banion, but her innocence is lost when the communist forces of leader Ho San (Weaver Lee) raid and decimate the mission. Ho San continues to persecute the priests, but struggles with his communist ideology when he receives disturbing orders from his leaders.