Crime reporter Keat Shevlin follows a hot lead down to Mexico, using a speedboat to get to Zapulteco, where the murder of "Honey" Hogan, a jewel thief, has just occurred. On the way, Keat rescues Barbara "Buff" Andrews, a female aviator who was forced into the ocean after the engine in her plane quit. Unwilling to postpone his trip to return her to San Diego, Keat takes her with him to Zapulteco, where he tries to put her on a train headed for home. She is headstrong, however, and is more interested in joining him on his mission. She wires her father, a United States senator, that she missed her train. Ready for adventure, Barbara dons Mexican clothes and goes to a cantina for a meal. Gangster Riley Ferguson, who had Hogan killed because he escaped with jewels that Ferguson had him steal, sends Ramirez, a local who has befriended him, to check out Barbara. Ramirez joins Barbara and Ferguson at the cantina, introducing himself as Mitchell, and the three enjoy themselves with a game of matchsticks. Keat is upset to find Barbara with the two men, and when he orders her to leave with him, she defiantly refuses. Seizing the opportunity, Ferguson invites Barbara to Ramirez's hacienda, and Keat reluctantly joins them. Keat has recognized Ferguson, however, and at the hacienda, convinces Barbara that she is in danger. They try to get away, but are captured. After Ramirez finds out Barbara is the daughter of a senator, Ferguson decides to kidnap her and hold her for ransom, but does not want to include Ramirez in the deal. He takes his hostages into the desert, using Pancho, one of Ramirez's men as a guide, but Ramirez locates them and takes command. Using a short-wave radio operated by Mopsy, one of Ferguson's thugs, the criminals wire Senator Andrews for the ransom. Keat is sent alone into the middle of the desert to pick up the $50,000, and when Harry Flint, one of Ferguson's men, tries to kill him on the way back, Pancho stabs him in the hand. Pancho rides away, and Ferguson is forced to rely on Ramirez as a guide out of the desert, even though Ramirez kills one of his thugs to save Barbara. At dawn they arrive at some houses on the edge of the desert, but it proves to be a set up, for Ramirez is actually a government agent. Ramirez has Ferguson and his surviving gang arrested. Barbara is glad to see her father, but when he wants to have Keat arrested for kidnapping, she takes a car and, with Keat in tow, speeds off to continue their romance.