As day breaks in the Sonoran Desert of Arizona, a wounded mountain lion limps toward a Papago Indian hut. The lion fears people, but today he is desperately hungry. And he has caught the scent of Birdwing and her mother. Then a loud thunderclap warns Birdwing, the mountain lion, and all creatures of the desert that danger is near. A flood will soon wash over the land—and some will not survive it.