As he removes a diamond necklace from the safe of the Versailles nightclub in Mexico City, a bartender is accosted by gun-wielding men, who shoot at him as he flees with the jewels. Later, in Los Angeles, insurance investigator Steve Hastings discusses the theft with Powers, his boss, and learns that the bartender is actually fellow detective Glenn Ames, who was sent to Mexico to track down the stolen necklace. Concerned that Glenn may be double-crossing the company, Powers assigns Steve to follow Glenn's sister Victoria, a singer who has booked a flight to Mexico. At the airport, Steve flirts with the attractive Victoria and, during the flight to Mexico, tries to gather information from her about Glenn. Victoria, however, resists Steve's advances and is reticent to talk about Glenn. After Victoria falls asleep, Steve searches her belongings and finds a telegram from Glenn, directing her to a certain address in Mexico City. Once landed, Victoria gives Steve a calculated kiss goodbye, then tries to rid herself of him by rushing off in a taxi. Steve, however, follows close behind in a cab driven by accomodating taxi driver Carlos. The address from the telegram belongs to a deserted villa, and as Victoria wanders from room to room, she becomes increasingly nervous. Just as Victoria is about to panic with fear, Steve surprises her. Grateful for Steve's timely intrusion, Victoria sends him to search the study. There Steve is attacked by two men, but is soon rescued by the vigilant Carlos, who shoots after the men and brings the police. At the police station, Steve reveals his mission to the local chief, who agrees that Victoria should be watched. Still playing the part of the ardent admirer, Steve registers her in a hotel room next to his, then makes a date with her for later that evening. After learning that the telegram was sent from the Versailles club, Steve discovers that Victoria is not in her hotel room. Concerned, Steve searches for Victoria, then heads for the Versailles with Carlos. To Steve's surprise, Victoria is there singing, having just been hired by club owner Joe Norcross. From a tense conversation he has with Benny, a bartender who knew Glenn, Steve deduces that Norcross is involved in Glenn's disappearance. Unable to talk freely with Benny, Steve decides to escort the unsuspecting Victoria to a garden party at Norcross' country estate, where Benny has been hired to tend bar. Upon arriving, however, Steve and Victoria learn that Benny has just been killed in an automobile accident. Suspicious, Steve questions Norcross' jealous girl friend, Dolores Fernandez, who is the club's regular singer, and finds himself becoming jealous of Norcross' attentions to Victoria. Anxious to upset Norcross, Dolores openly kisses Steve, who is then rebuffed by an equally jealous Victoria. Steve drives the angry Victoria back to the hotel and finally confesses his mission to her. After Victoria bids Steve a curt goodbye, Carlos, who has been waiting for her return, telephones Norcross. A Norcross spy, Carlos then intercepts Pancho Gomez, a peasant boy who is delivering a package to Victoria, and learns of Glenn's whereabouts. The boy takes Victoria and Carlos to his family's farm house, where Glenn has been recuperating from a gunshot wound he suffered while fleeing from the club. Carlos calls Norcross at the club just as Steve is questioning him about Benny. As Carlos tells Norcross where Glenn is hiding, Steve listens in on an extension, but is quickly knocked out by Norcross' men. Steve awakens at the farm house, where Norcross is holding Victoria prisoner and is torturing Glenn to reveal the whereabouts of the stolen jewels. Glenn refuses to talk, but communicates silently to Steve that the necklace is inside a doll owned by Pancho's little sister Floracita. To stall, Steve convinces Norcross that the jewels are in the package that Pancho delivered to the hotel, and Norcross sends Carlos to retrieve them. Just after Carlos returns empty-handed, Norcross sees Floracita playing with the necklace and starts to grab it when Luis Otero, a local policeman assigned to watch Victoria, bursts in and shoots Norcross. After a shootout with the police, the rest of the gang is apprehended, and Glenn is cleared of all suspicion. By pretending that Dolores wants to hire him, Steve then tricks Victoria into agreeing to a quick wedding.