Cousins Teresa and Jessica, and Jessica’s boyfriend Caleb, are vacationing at a lakeside cabin when a seemingly ill Jessica scalps Teresa and decapitates Caleb before levitating above the lake.
One day earlier, upset at learning she is pregnant, guitar technician Beth visits her sister Ellie, a tattoo artist and single mother to teenagers Danny and Bridget, and child Kassie, in their home at Monde Apartments, a condemned Los Angeles apartment complex. The building is shaken by an earthquake while the children are in its basement parking lot, uncovering a concealed chamber. Danny investigates it, discovering religious artifacts, three phonograph records from 1923, and a strange book that he takes up to his room, believing he could possibly sell it and use the money to help Ellie. The initial record details rejected efforts by a priest to research the book, revealed to be one of three volumes of the Naturom Demonto. The subsequent record reveals the priest continued his research in secret and recites an incantation that summons demonic entities known as Deadites.
