The Third Scour - Edward W. Robertson

The young sorcerer Cally has routed the Mallish invaders from Collen, the home of his love Myla. For the first time in a long time, the land is at peace. But few believe it will last. Brought before Collen’s highest authority, the Pastkeepers, Cally is told a deep secret: the Rod of the Devil’s Tongue, the artifact he used to defeat the Mallish, has even greater powers than he knows. If he can unlock them, he can drive the Mallish out of Collen forever.