|Alec Guinness||Captain Henry St. James|
|Yvonne De Carlo||Nita St. James|
|Celia Johnson||Maud St. James|
Captain Henry St. James heads a ferryboat that regularly moves between Gibraltar and North Africa, and he has a different life in each location. In Gibraltar, he is married to Maud, a subdued and dedicated housewife. In Morocco, he has another wife, the tempestuous Nita, who enjoys the fast-paced nightlife. Henry enjoys this arrangement, with neither woman knowing of the other, until both women become dissatisfied with their one-sided lives.