In the 1970s, in the United States, there existed a generational off-the-grid cult that believed Satan was returning to claim his throne. To ensure victory in the ultimate Unholy War on the horizon, their cult leader (Susan Lanier) requested more recruits. Velvet, a runaway hippie, is trapped in a dilapidated house alongside a colorful group of strangers. They each have a choice to join the family or fight to survive one of the most brutal satanic slayings in the annals of American history.