A polio epidemic is sweeping California. Thirteen-year-old Lena, a Nuwä/Kawaiisu Indian girl, must find the great healer Yahwera and get the medicine her best friend, Sara, and so many others need. But Yahwera refuses to help unless Lena saves the annoying and foolish trickster Coyote. To do this, both girls must travel back to the time when animals were people and learn what it truly means to save Coyote, before it's too late for everyone.