Night Masks. The Cleric Quintet

Cadderly the warrior-priest discovers a magical book whose secrets may help him to defeat the Chaos Curse once and for all Cadderly's spiritual and moral wrestlings reach a crescendo upon his discovery of the mysterious Tome of Universal Harmony. While he is eager to defeat evil, his battles against the Chaos Curse have taken him far from his scholarly inventor's life, and the magical book from his priestly order calls to him in ways he cannot fully comprehend.
But adventure isn't finished with the young cleric yet. Cadderly and his friends face great danger from a sinister killer and the assassins of the Night Mask, all of whom lurk in the streets of the city of Carradoon. With the dreaded Chaos Curse still at large and new enemies at every turn, can Cadderly find both his faith and his warrior's courage before it's too late?