Captain Underpants and the Revolting Revenge of the Radioactive Robo-Boxers

When we last saw our heroes, George and Harold, they had been turnedinto evil zombie nerds doomed to roam a devastated, post-apocalypticplanet for all eternity. But why, you might ask, didn't theamazing Captain Underpants save the boys from this frighteningfate? Because Tippy Tinkletrousers and his time-traveling hijinksprevented George and Harold from creating Captain Underpants inthe first place! Now, having changed the course of human historyforever, they'll have to figure out a way to CHANGE IT BACK.Could this be the end for Captain Underpants?!!