In a mission in China in 1935, Agatha Andrews is a rigid missionary beset by Mongolian bandits led by Warlord chief Tunga Khan. With her are her assistant Jane Argent, staff members Emma Clark, Miss Russell and Miss Binns, head of the British mission, Charles Pather, a teacher at the mission and his pregnant wife Florrie. When Dr. D.R. Cartwright arrives, she agrees to sacrifice herself to the Tunga Khan in exchange for his letting the ladies go free.