It goes into what brings about genocide amongst otherwise and previously ordinary folk - turning good neighbours against each other etc; how the unthinkable somehow becomes psychologically possible. Several case studies are used from history, including Rwanda, Nazi Germany, and Armenia, amongst others - and finds quite clear stages which are paralleled in all cased. Real sociological experiments are used to demonstrate the same individual aspects in modern people - things like tribalism with football team supporters, or that people tend to elect those most able to convincingly lie as leaders - all done in ways that will likely take you from skeptic to jaw-dropped.