House of Demons

In this, Gwen, Matthew, Katrina, and Spencer were best friends for years, until a terrible tragedy tore them apart, and left all of them in a state of arrested development. Ten years later, they're reunited for a destination wedding to stay together in a rented house. What they don't know is 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.