A ship off the coast of Florida is becalmed, and the sailors are heard voicing their fears as the Spanish nobleman Solano sings of his obsession with the fountain of youth he has learned of and come to discover. Thunder announces the approach of a storm that hurls the ship to destruction. On the Florida coast, the young American Indian girl Watawa finds Solano, seemingly the sole survivor, and very weak. Other Indians arrive and their chief Wapanacki has Solano borne to their camp. While Watawa grieves for her people and plots revenge on the white man, Wapanacki questions Solano about his mission. The chief advises him to seek out the seer Talum Hadjo in the depths of the swamps and appoints Watawa as his guide. Solano is struck by her beauty. They travel together to Talum Hadjo's hut. Solano stays outside while Watawa consults the wise man, who advises her that her vengeance is unnecessary: the fountain of youth will bring death to anyone who is not properly prepared for it. Their journey continues, with Watawa making the uncomfortable realisation that she has fallen in love with Solano. Eventually she is forced to own it, and they embrace. Meanwhile the mists clear from the magic fountain, and the god Unktahé appears. Unable to dissuade Solano from drinking from the fountain, Watawa does so herself, and dies. Solano follows her example and falls dead upon her breast.