Hwani's family has never been the same since she and her younger sister went missing and were later found unconscious in the forest, near a gruesome crime scene. The only thing they remember: Their captor wore a painted-white mask.
To escape the haunting memories of this incident, the family flees their hometown. Years later, Detective Min—Hwani's father—learns that thirteen girls have recently disappeared under similar circumstances, and so he returns to their hometown to investigate... only to vanish as well.
Determined to find her father and solve the case that tore their family apart, Hwani returns home to pick up the trail. As she digs into the secrets of the small village—and reconnects with her now estranged sister—Hwani comes to realize that the answer lies within her own buried memories of what happened in the forest all those years ago.