For three consecutive nights, Lin Zhi has been trapped in the same nightmare: a round house halfway up a mountain shrouded in white mist, a little girl falling from a swing into the water, and groups of children lining up to walk toward danger. Returning to the old family home to help her mother manage the property, she is horrified to discover that the nightmare's cursed location truly exists. The abandoned amusement park where a tragedy once occurred has now been turned into a mountain spring bathhouse used by the villagers. Deep inside the bathhouse, an iron door remains locked, a door everyone avoids at all costs. The amusement park tragedy from years ago was deliberately buried. A developer eager to profit from demolition applies mounting pressure, her mother refuses to discuss the past, and the villagers maintain a collective silence. As the nightmare seeps into reality, old files and secret recordings gradually come to light.