One day, Ga-In, who has been suffering from Ripley syndrome, meets high school friend Eun-Jung after 7 years hiatus. She feels jealous of her friend who seems to have everything she ever wanted in her life: gorgeous house, husband, children and even her job. Ga-In's envy turns into obsession as she begins to think of herself as Eun-Jung, trying to assume her very identity, including seducing her husband and stealing her child.