Terri says she trusted and thought she knew her 15-year-old daughter, Sierra — who she believed was a popular teen, earning good grades — until Sierra disappeared and was discovered by police, days later, after witnessing a murder. Terri says she then learned that Sierra had been living a very different life — experimenting with drugs, meeting men online and having sexual relationships with them — many of whom were twice her age. Despite Sierra's alleged traumatic experience, Terri says her daughter continues to travel down a troubled path. Can Dr. Phil get to the root of Sierra's behavior? What warning signs did Terri miss? And, how might she be enabling her daughter? If you’re a parent, you can’t afford to miss this all-new Dr. Phil! This program contains strong sexual content. Viewer discretion advised.