In the kingdom of Xoana, Lina Inverse and Gourry Gabriev unexpectedly run into their old companions, Zelgadis Graywords and Princess Amelia Wil Tesla Saillune. Upon reuniting, the friends easily thwart the dastardly world-conquest plans of the King of Xoana and his daughter. Shortly thereafter, it is revealed that Zelgadis is searching for the world's most valuable magical tome, the Claire Bible, hoping to find a way to restore his human body among the many secrets it holds. Despite his objections, the rest of the group decides to join the quest after learning of his mission. However, just as they are wondering where to begin their search for the legendary book, they encounter a mysterious priest named Xellos, who claims he may be able to assist them in their pursuit.