Fanatic (1965)

young pat carroll visits the mother of her first boyfriend, who died in tragic circumstances. the woman, who lives with her two servants harry and anna, immediately appears visibly upset. he decides to stop for the night and leave the next day, but does not know that waiting for her there is a spiral of violence and terror, unleashed by the sick mind of the mother-in-law who intends to purify her and make her reach her son in the world of the dead.