Have George and Harold completely lost their minds? Their time-travelling purple potty has landed them in a crazy place where the teachers are always nice, the cafeteria serves delicious food and the school principal, Mr. Krupp actually thinks they're funny. Something is very wrong and it gets even wronger when the boys pet pterodactyl-Crackers and Sulu the Bionic Hamster are kidnapped by George and Harold's evil twin look-alikes. Now George and Harold must face their cleverest enemies yet: Themselves! Could this be another job for the amazing Captain Underpants?