Though Jamie's mother is apprehensive about her bookish and solitary son's get-well summer on an uncle's Montana ranch -- Jamie is soon riding a horse, chatting with old Cheyenne leader White Fang, and palling with White Fang's grandson Horse more easily than he ever made friends at home. One day when White Fang is absent from his customary station which is an outcropping of caveriddled rocks containing ancient Indian pictographs, Jamie finds there an old medicine bag that the rattlesnakes have displaced from a high ledge. Later, in a series of dreams that connect like chapters in a stow, he pieces together information from his books, White Fang's stories about Round Stone, an older, outsider-type brother killed at Little Big Horn, his own insights and possible a message from Round Stone, the likely possessor (Jamie concludes) of the medicine bag. Convinced that he must return the bag to appease Round Stone and revive an ailing White Fang, Jamie with Horse's aid makes a dangerous cliff-edge descent and discovers that there is indeed a wrapped Indian corpse where he had suspected Round Stone was buried. Lampman proficiently integrates the facts and the power of Cheyenne culture and history with the mystery of the medicine bag, the adventure of returning it, and the maturing transformation of Jamie into Jim.