Gwen, Matthew, Katrina, and Spencer were best friends for years, until a terrible tragedy tore them apart. Ten years later, they reunite in a rented house for a destination wedding. What they don't know is that in the late '60s, the house was home to a Manson Family-like cult run by Frazer, a charismatic former scientist pushing the boundaries of human consciousness. His experiments echo through time and manifest everyone's darkest fears and memories, blurring time as Frazer's cult and the present day collide over the course of one long night, where everyone must confront their darkness or be destroyed by it.