The film tells the story of Susan, who receives a manuscript from her ex-husband, whom she divorced 20 years earlier, asking for her thoughts on the novel he has written. As Susan reads the novel, she is drawn back into her own past through the story within the book, which follows a family trip that descends into a terrifying cycle of violence. The novel forces her to confront her former marriage and the decisions she made years ago, compelling Susan to face the dark truths about herself that she has long chosen to ignore.