Aspiring YouTuber Gi-ho stages a fake seance for viral content, but Ja-young joins, seeking her missing sister Seo-woo. In an underground cistern, Seo-woo volunteers as the “possessed,” but when she…

Trapped in the deadly cursed “Mafia Game,” the students of Yoo-il High must play the game to survive, while unraveling the mysteries behind the curse.