Changeling

Kate and Zoe are a normal, loving couple with a healthy relationship. They have a nice home, great friends and good jobs. When Zoe spends a weekend at her estranged childhood home, visiting her terminally ill mother, Kate doesn't worry about the lack of communication. The community she came from is remote, and it's not easy to get a decent 'phone signal there. However, as time goes on, Kate does start to fret. She is contemplating calling the police just as Zoe walks in, unharmed, but a seemingly changed person. Kate starts to experience and to see things that defy rational explanation. Are her nightmares and hallucinations just due to stress and lack of sleep, or something more sinister? Was it really Zoe that has come home to her, or was it someone (or something) else?