Captain Underpants and the preposterous plight of the purple potty people / Pilkey, Dav

Crackers and Sulu, the Bionic Hamster, finds themselves in a backwards universe where George and Harold's own evil twins rule the school with the help of the wicked Captain Blunderpants.

Crackers and Sulu, the Bionic Hamster, finds themselves in a backwards universe where George and Harold's own evil twins rule the school with the help of the wicked Captain Blunderpants.

When George and Harold use their traveling purple potty to travel to another dimension where the school is nice and the principal, Mr. Krupp, thinks they're funny, they meet up with their evil twins and must face their cleverest enemies ever -- themselves.

The time-traveling Purple Potty has landed George and Harold in a crazy place where the teachers are always nice, the cafeteria serves delicious meals and their twin look-alikes are evil.