The fourth season focuses on the search for a missing Navajo girl, which takes Leaphorn, Chee and Manuelito from the safety of Navajo Nation to the gritty terrain of 1970s Los Angeles in a race against the clock to save her from an obsessive killer with ties to organized crime.

Followed by Darby Harper, who is granted the ability to see ghosts after suffering a near death experience in her childhood. Then, she runs a side business counseling local spirits in her spare time.