Clan fighting over a powerful totemic mask has brought the Mound Builder people of the Great Lakes region to the edge of destruction. It is up to Star Shell, daughter of a Hopewell chief, to rid her people of this curse. Along with her companions: Otter, a trader; Pearl, a runaway; and Green Spider, either prophet or madman, she braves the stormy waters of the lakes to reach the majestic waterfall known as Roaring Water. She is determined to banish the mask forever to a watery grave. But vengeful clan members are close on her heels, and they have a similar fate planned for her.