Book 8 in the Ranger’s Apprentice series takes Will, his mentor, Halt, and their friend Horace to the kingdom of Clonmel. There Halt confronts painful memories from his past, while the three friends work to subvert a devious plot by a cult religion that seeks to gain control by sending in bands of marauding invaders, then offering a god that can protect the people from them. Although the many references to previous adventures slow the pace at times, there’s wit as well as action here, and the revelation of Halt’s backstory adds a new dimension to the saga.