Even with a mix of narcissism, paranoia, and undeniable charisma, cult leaders normally don't become violent. But when they do, the consequences can be staggering. With an army of loyal followers at their command, they have the power to act out their most deluded fantasies on a scale that rivals the worst serial killers. Analyzing three of 20th century's most deadly cult leaders, Dr. Stone investigates. Vincent Bugliosi, the man who prosecuted Charles Manson, explored one of the world's most shocking crimes, and into the mind of a notorious murderer.