In this world of myth and faery tale transportation is by one's own hoofs or wings or the wings of the great-moth. Long distance communication is by "speaking mind." Two tiny, six-winged faery go to seek the riders of the great-moth to learn the secret of the mother moth, twah. Led by the Black Faery, Sorro of the many dreams, they visit the mountain home of Gormaak, the Centaur. He guides the Faery and the Twahin across the glaciers to the edge of a high plateau. The small folk plunge into the unknown and come again to the City-on-the-Edge-of-the-World, the ancient home of their common ancestors.