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?