When a man claiming to be long-lost Uncle Fester reappears after 25 years lost, the family plans a celebration to wake the dead. But the kids barely have time to warm up the electric chair before Morticia begins to suspect Fester is fraud when he can't recall any of the details of Fester's life.

Wednesday Addams is sent to Nevermore Academy, a bizarre boarding school where she attempts to master her psychic powers, stop a monstrous killing spree of the town citizens, and solve the supernatural mystery that affected her family 25 years ago — all while navigating her new relationships.