The Heiress tells the story of a family that is bound by dark powers from the past as their Matriarch, Auntie Luna (Maricel Soriano) a mambabarang who got her powers to a mamalarang is in need to pass on the powers that she possessed or else the mamalarang will take her, her only heir is her niece Guia (Janella Salvador). Guia grew up with her Auntie Luna as her mother, Carmen (Sunshine Cruz) works abroad not knowing what her Aunt Luna really is little by little Guia is discovering spooky things and experiencing paranormal incidents that will lead her to discovering that she is the heiress. Will Guia accept her Auntie Luna's power or will the Mamalarang takes toll on both of them?