Mytyl and her brother Tyltyl are peasant children who are led on a quest for the Blue Bird of Happiness by the Queen of Light, who gives them a hat with a magic diamond that allows them to call forth the souls of all things, both living and inanimate. On their journey, they are accompanied by the human personifications of a dog, a cat, water, sugar, bread, light, fire, and the like. They visit the kingdoms of the past and future and the queendoms of night and luxury, at each place absorbing more wisdom. Eventually they discover the blue bird they've been seeking has been in their own backyard all along...