 Dolores Berthier is a well-to-do housewife living with her husband, Andrés, in an elegant old building in latter-day Mexico City. After Eva, her neighbour and friend, is savagely murdered on her doorstep, Dolores freaks and starts to go delusional. Concerned, Andrés asks her to meet with a psychiatrist, meanwhile she finds in a book at Eva s the address of Madame Endor, a mysterious sorceress who seeks to aid her, for it seems that, unbeknownst to her, Dolores is entangled in a web of voodoo and black magic. As her kindly doctor tries to figure out what is going on and joins forces with Madame, who finds herself dying, Dolores s marriage starts to come apart at the seams on lieu of certain shocking revelations of murder, treachery and deceit, and an eerie zombie-like figure starts to stalk her luxurious apartment, seeking to settle an old score...