George and Harold have to figure out how to fix history in the tenth book in this #1 New York Times bestselling series by Dav Pilkey, the author and illustrator of Dog Man! George and Harold have been turned into evil zombie nerds doomed to roam a devastated, postapocalyptic planet for all eternity! Unfortunately, the boys can`t count on Captain Underpants for help because Tippy Tinkletrousers and his time-traveling hijinks prevented George and Harold from creating him in the first place! With T ...