Gaby (Hedy Lamarr) arrives in Algiers engaged to a fat, vulgar borderline-loathsome older man who clearly regards her as a trophy bought and paid for. Why she needed this creep isn't clear. What is clear is her falling in love with the jewel thief Pepe Le Moko (Charles Boyer) who abandons the devoted and clinging Ines (Sigrid Gurie) for this right-off-the-boat hothouse beauty. A Parisian police official (Walter Kingsford) is in Algiers determined to collar Pepe.