The Book of Sages

In Fantasia, young Atreyu is sent on a magical journey to save the childlike Empress, because the evil forces of nothingness threaten the existence of this world. The sister of the Empress, the dark princess Xayide, strives for the sole power there. That's why she sends Gmork, the werewolf and frontier crosser between the worlds, to Bastian to prevent him from reading the magical book. It is the beginning of a long battle.