This book is about a boy named bobby pendragon who happens to be a traveler that travels to diffrent territories and saves them from an evil man named Saint Dane. They travel to a territory called first earth. First earth is earth in the 1937's when the hindinburg blew up. It turns out that the hindinburg crash turned out to be the best thing that happened in world war 2. If the hindinburg didn't crash, the nazizs would have gotten their hands on a blueprint in the hindinburg that was for a atomic bomb. If the hindinburg didn't blow up then all of earth's history would have been very diffrent from what it is today in this story. Bobby saves the earth along with his friend Spader, a traveler from a territory called Coral, and Gunny, a traveler from first earth.