The episode recounts the disappearance and murder of Elizabeth Sullivan, a 31-year-old mother of two, from San Diego in 2014. It explores her complex personality, marked by brilliance and impulsivity, along with her struggles with Borderline Personality Disorder. The narrative details her tumultuous marriage to Matthew Sullivan, highlighting the pressures of military life and her clandestine affair. The discovery of her body in 2016, two years after her disappearance, unveiled a violent crime and led investigators to her husband, who was later convicted. Ultimately, the text examines the investigation that brought her killer to justice while reflecting on the profound loss and lasting questions surrounding her tragic death.