Dave Passenger is a Naval Criminal Investigative Service agent in San Diego, whose ex-wife has just sent their rebellious 14-year-old daughter Erica to live with him. On the day of Erica's arrival, Dave is assigned to investigate the murder of a 17-year-old runaway from the town of Noble, Arizona. When a young sailor from that town emerges as a prime suspect, Dave goes to Noble to try to find him. With no one to care for his daughter, he takes her along. Dave and Erica are unwelcome in the old-fashioned town until they meet local Sheriff Bast, who makes a show of cooperating in Dave's search for the killer. When Dave discovers that Noble is a community of polygamists, his search takes a new direction and he realizes that to crack the case, he must earn the trust of this large, well-guarded family. To complicate matters, Dave becomes involved with Ingrid Bast, the Sheriff's daughter. Meanwhile, Erica flirts with Ingrid's younger brother, a close friend of the murdered girl's sister.
