As Germany is in the throes of losing World War II, a number of wealthy Nazis and some French sympathizers head for South America in a German submarine leaving from Oslo. The film's narrator is a French doctor (Henri Vidal) who has been kidnapped to tend a sick woman, Hilde Garosi (Florence Marly), the wife of one man and the lover of another, both aboard. The doctor realizes he will be murdered at any point once the woman has recovered so he tries various stratagems to escape. All fail.