Gr 4–7—A viscerally affecting story of war, loss, and the power of friendship. Pennypacker, author of the exuberant "Clementine" series (Disney-Hyperion) and the charmingly morbid Summer of the Gypsy Moths (HarperCollins, 2012), here displays not only her formidable writing skills and a willingness to stretch her storytelling into increasingly complex narrative forms but also her ability to tackle dark and weighty themes with sensitivity and respect for the child reader. Set in an intentionally undefined time and place that could very well be a near-future America, the novel opens with a heartbreaking scene of a tame red fox, Pax, being abandoned at the side of the road by his beloved boy, Peter. Perspectives alternate between the boy and the fox, and readers learn that a terrible war rages in this land. Peter's father is about to leave for the frontlines, and while he's away, Peter must live with his grandfather out in the country—and his father makes it clear that there is no place for Pax in Peter's temporary home. Almost as soon as he arrives at his grandfather's, Peter is overcome with guilt, and he sets off under the cover of darkness to trek the 300 miles back to his home, where he prays he'll find Pax. The loyal fox, meanwhile, must figure out how to survive in the wild—though never losing hope that his boy will return for him. As the protagonists struggle to reunite in a world in the grip of violence and destruction, they each find helpers who assist them on their respective journeys: Peter breaks his foot and is rehabilitated by Vola, a hermit suffering from post-traumatic stress disorder, while Pax is taken in by a leash of foxes who teach him the basics of foraging and hunting. Pennypacker doesn't shy away from some of the more realistic aspects of war, though she keeps most of the violence slightly off-screen: in one scene, the wild foxes define war for the naive Pax as a "human sickness" that causes them to turn on their own kind, akin to rabies; later, as the battle creeps closer, several creatures are maimed and killed by land mines. Black-and-white drawings by Klassen offer a respite for readers, while adding to the haunting atmosphere.With spare, lyrical prose, Pennypacker manages to infuse this tearjerker with a tender hope, showing that peace and love can require just as much sacrifice as war. VERDICT A startling work of fiction that should be read—and discussed—by children and adults alike.—Kiera Parrott, School Library Journal