Carrie, a young religious fundamentalist, is abandoned by her missionary father and has to move in with her mother, who is now in a committed lesbian relationship and has a biological child named Tia. Carrie's new life is not the only thing that is bothering her: it is the house they moved into. Creepy things begin to happen that lead Carrie to believe that the house is haunted. As Tia's new parents leave for a business trip, Carrie must take care of her stepsister. In one terrifying night, Carrie and her boyfriend Aaron conduct an exorcism to rid the house of its supernatural presence but instead find the house possessed by a monster. Now, Carrie must overcome her own beliefs and do whatever it takes to protect her little sister.