Thunder Falls chronicles the transformation of Leopold Wolf from a naive young man into an outspoken advocate for Native American rights during the late 1800s. Leo works for the Carlisle Indian School, an institution governed by the motto "kill the Indian, save the man" and notorious for the harshness of its abuse, neglect, and victimization of the children under its care. Leo's quest takes him to Lakota territory, where elder and holy man Black Elk has a vision of Leo recovering the tribe's Sacred Pipe, stolen years ago. Leo's journey into the caverns of the Black Hills reveals extraordinary phenomena about the Lakota and about himself. Within the caverns, Leo encounters the red wolf, Thunder Falls, and the Soul Tree, all of which guide him toward his destiny. While pursuing the eternal love of Sarah Cameron-niece of a senator notorious for his enmity against the Lakota, Leo crosses the country with Buffalo Bill's Wild West Show and ultimately risks his life for the people he has come to care for.