A gripping tale of romance and crime set in the dark alleyways of the Casbah in Algiers. Charles Boyer is gangster Pepe Le Moko who has been on the run from the authorities in his native Paris. The Casbah is a safe haven, where he mixes with people similar to himself; but years of being trapped in a routine without change has taken its toll and he becomes homesick for the lights of Paris. His spirits are lifted when Gaby (Hedy Lamarr) appears. She's elegant and beautiful and oozes sophistication - all reminders of his previous life in the clubs and bars of Paris - unfortunately she's also the mistress of an older man; and Pepe also has Ines (Sigrid Gurie), not known for her even temper. The jewel bedecked Gaby is too much of a prize for Pepe to ignore, even though the feisty Ines is ignored at your peril. But police Inspector Slimane (Joseph Calleia) is only too well aware of the unfolding love tangle and just bides his time before landing his biggest prize yet.