Dexter has developed the pinnacle of technology called "The Clone-a-Matic." Unfortunately, his elder sister Dee has interfered once more and has cloned herself by mistake. Additionally, there is more than one instance of her. What a nightmare! Dexter's Laboratory has become infected with miniature versions of Dee Dee, who are intent on ruining all of Dexter's brilliant research! It is up to the players to assist Dexter in catching Dee Dee, restoring normalcy to Dexter's laboratory, and returning Dee Dee to her single state before Mom calls for supper.