A student with mild physical and mental disabilities, Yongzhan, drowned in the river. After investigations by the prosecutor and forensic examiner, the case was closed as non-homicidal, an accidental drowning. Lin's mother, suspecting foul play in her beloved son's death, embarked on a solo investigation. Despite layers of reasoning, she couldn't uncover any clues and directed her dissatisfaction and resentment toward her stepdaughter, Liwei. What was once a happy home is now only housed two sorrowful women at odds with each other. After the funeral, everything seemed to settle like dust in the wind. However, a new wave stirred when a roll of film came to light. Liwei sat alone in a small cinema, watching a movie as the shimmering water played on the big screen. Her secret and the truth Lin's mother sought remained buried in the shadows of their hearts.