In a small suburban town, six friends in middle school—Lily, Amelia, Will, Jack, Tom, and Emily—find an old board game hidden in the back of the school library. Intrigued by its mysterious design and strange instructions warning players to "make the right choice or suffer the consequences," they decide to play it at their favorite spot: an abandoned treehouse deep in the woods. As each turn progresses, the game intertwines with their real lives.