Gr 5–8—Having defeated the Riven and their creepy leader, Mr. Jericho, in The Box and the Dragonfly, Horace and Chloe are busy learning some of Horace's mom's secrets, including that she is a Tuner (someone who uses a harplike object to cleanse and tune up the Keeper's magical talismans). Then they are introduced to Brian, whose abilities are so unique that he can never leave his underground workshop. Meanwhile, a girl named April acquires an unusual piece of jewelry, which amps up her empathy toward animals but also makes her a target for the Riven and compels her to follow a mysterious woman (who may be neither trustworthy nor completely sane) and boy on a perilous journey. Chloe and Brian are especially interesting characters, both dealing with issues of trust and responsibility with snarky humor and bravado. Once again, there is a lot of jargon and complicated mythology to get through and a fair amount of violence. Many questions are left unanswered, leaving the door open to further adventures. VERDICT Readers who are willing to make the effort will find this a rewarding and thought-provoking fantasy.—Mara Alpert, Los Angeles Public Library