The series is based on the eponymous podcast by iHeartMedia, which tells the story of Melissa Jesperson-Moore, a participant in Dr. Oz\'s show. At the age of 15, she found out that her father, Keith Hunter Jesperson, was a serial killer known as the \"Happy Face Killer.\" As she grew older, Melissa changed her name to hide the secret and completely severed ties with her father, who is serving a life sentence.