Book two of Stiefvater’s Raven Cycle shifts from character-driven voyage of discovery to more of a paranormal thriller, ratcheting up the violence as the plot grows more complex. After the transformative events at Cabeswater in The Raven Boys, the context in which Gansey, Blue, Adam, Ronan, and Noah operate is further altered by the arrival of the Gray Man, a self-described hit man who replaces Barrington Whelk in providing occasional adult narrative perspective. The Gray Man brings with him the machinations of larger, previously unknown forces as he takes orders from a voice on the phone to hunt the Greywaren, the identity of which is revealed early on. But this book largely belongs to the loose cannon that is Ronan, as he works to better understand his supernatural abilities and their connection to his family. While Stiefvater’s offbeat, acutely observed characters continue to grow, they have shifted from developing a group interaction to reacting against one another, making this installment more tense and foreboding than its predecessor—and every bit as gripping. Ages 14–up. Agent: Laura Rennert, Andrea Brown Literary Agency. (Sept.)