Detectives Sallie Dillian and Cliff Jewell investigate a female skeleton found in the desert. Along with forensic anthropologist Laura Fulginiti, they work to determine who the mystery woman is. At first, they don't even know if she was murdered. But they use the scattered forensic and physical evidence to determine her identity and crack the case; an 18-year-old is shot in the head as a party of hundreds of high school students is breaking up. Because the teen is not expected to survive, homicide detectives Sandy Rodriguez and Tom Kulesa are called to the scene. Witnesses describe the shooter as a black male in a ski mask. In an intriguing development, there is a report of another non-fatal shooting that took place nearby, where the victim also described the shooter as a black male in a ski mask. Rodriguez and Kulesa must determine if the two events are related, who would have been after the victim and why.