Swimming instructor Young-eun becomes deeply troubled by her six-year-old daughter’s dark, violent behavior, especially after a tragic incident with their puppy. Twenty years later, orphan Min finds her life increasingly disrupted when mysterious Hae-young infiltrates her carefully controlled existence. As unsettling events and disturbing backstories surface, consequences turn lethal. Directors Lee Jung-chan and Kim Yeo-jung’s debut is a gripping, female-driven thriller highlighted by nuanced performances from Kwak Sun-young, Kwon Yu-ri, and Lee Sul, masterfully weaving suspense, familial bonds, and hidden secrets into its tense narrative.