On the east coast of New Zealand, the Whangara people believe their presence there dates back a thousand years or more to a single ancestor, Paikea, who escaped death when his canoe capsized by riding to shore on the back of a whale. From then on, Whangara chiefs, always the first-born, always male, have been considered Paikea's direct descendants. Pai, an 11-year-old girl in a patriarchal New Zealand tribe, believes she is destined to be the new...