From the 1995 sarin nerve gas attack in Japan to the Manson murders, some of the most horrific cult killings were carried out not by the cult leaders who planned them, but by willing followers. How do these members become so entrenched in cult thinking that they become active participants in evil? Dr. Stone unearths the psychology of persuasion and indoctrination by interviewing surviving cult member Tim Carter, one of only three to survive the 1978 Jonestown massacre. And he'll meet face-to-face with Ron Luff, serving a life sentence for his part in the cult murders of the Avery family. Is there something psychologically unique to violent cult members, or can any one of us be drawn in?