>When we last saw our heroes, George and Harold, they had been turned into evil zombie nerds doomed to roam a devastated, postapocalyptic planet for all eternity. But why, you might ask, didn't the amazing Captain Underpants save the boys from this frightening fate? Because Tippy Tinkletrousers and his time-traveling hijinks prevented George and Harold from creating Captain Underpants in the first place! Now, having changed the course of human history forever, they'll have to figure out a way to CHANGE IT BACK.La última vez que vimos a nuestros héroes, Jorge y Berto, estos habían sido convertidos en zombis destinados a deambular por toda la eternidad en un planeta destruido. Pero, por qué razón el Capitán Calzoncillos no salvó a los chicos de ese destino? Para empezar, el profesor Cacapipí y sus alocados viajes en el tiempo impidieron que Jorge y Berto crearan al Capitán Calzoncillos!