Rhonda Collins MD is a popular physician at a Corpus Christi family clinic. One day she leaves on her lunch break and never returns. Her best friend, Linda, another physician, calls the Police Department to ask for their help in finding her, but Rhonda hasn't been missing long enough. The media learns about the missing woman and everyone in the city is caught up in the mystery of what happened to a beautiful doctor.
Pressed by the media, the police chief reluctantly appoints two detectives, veteran Sgt. Stan Belkin and newbie, Maria Gonzales, to the case. The two begin an uneasy relationship, which sometimes becomes warlike.
Sandra Lewis, Rhonda's stepsister, who has an amazing resemblance to her, has been seen leaving the restroom near the credit union, wearing Rhonda's clothing. As the PD and Rhonda's doctor friends try to find her, her stepsister attempts to flee to Mexico while dealing with a series of mishaps.
Linda's husband carries a secret. She wonders if she ever knew her best friend. Did either of them have anything to do with Rhonda's disappearance? Why did the stepsister leave town?