After an encounter with the school bully and his gang, Peter decides to stay in Jumanji and is slowly transformed into a Manji mask-warrior, while Alan discovers the key to the secret back door of Jumanji.

When Peter brings a computer with him into the game to help figure out how to rescue Alan, it falls into the hands of a mad inventor who uses it to gain control over the inner workings of Jumanji.

Alan manages to turn Van Pelt's own tactics against him and defeat the hunter, but Jumanji simply replaces him by transforming Peter into a miniature replica of Van Pelt.

When the kids and Alan finally escape from Jumanji, Peter brings a harmless-looking animal back with him which proceeds to grow bigger (and hungrier) every time he tells a lie and soon threatens all of Brantford.

Alan and the kids get trapped between the warring red ants and blue ants.