Pendragon: The Rivers of Zadaa

As strange as the title sounds, this book (the sixth in a series) is actually rather good. The series is all about a boy named Bobby Pendragon who is a Traveler, which means he can travel between dimensions to help the people and creatures that live there. Bobby's greatest enemy, the thing that threatens the what ties all of the universes together, is jumping from world to world, trying to take over each one or destroy it. His name is Saint Dane (ironic, right?). In this book, Bobby is in Zadaa, a dry and dusty land where the population consists of menacing warriors. His friend, Loor, called him to the world when two tribes, the Rokador  and the Batu are on the verge of war. Saint Dane has somehow caused all of the water in the land to dry up and disappear, and each tribe blames the other. Now Bobby must hunt down Saint Dane once and for all... or risk another world falling to Saint Danes evil influence.