When a Cuban man is killed on a New York street, the investigation leads to Havana and the man running an alien smuggling ring known as Palinov (George Macready). Pete Karczag (John Hodiak) is the immigration detective assigned to the case in Havana. To infiltrate the ring, he poses as a Hungarian refugee desperate to gain passage to America. While negotiating his trip he meets and falls for beautiful Marianne Lorress (Hedy Lamarr), who is also hoping to make the illegal journey. It's a Latin dance with frequent lead changes as Palinov and Pete struggle for the upper hand and the attentions of Marianne. As tautly directed by noir specialist Joseph H. Lewis (My Name Is Julia Ross, Gun Crazy), the winner of this high-stakes game is unknown until the climactic finale on a fog-shrouded dock.