Char's mother, Angela, has inexplicably disappeared. All that remains is her abandoned car. When she returns home without explanation, it becomes clear to Char and her grandmother, Rita, that something is amiss. She might look and sound the same but Angela's behaviour has become increasingly frightening, as if she has been replaced by a malevolent force. As Halloween night looms, a night steeped in ancient myth and legend, Char realises that she is the only one who can save her, even if it means potentially losing her forever.