Contemplations on Many Worlds was a book written by Khadgar. In the book, he discusses the cosmology of the universe. Though it sparks a great many debates, the book is the common starting point for many discussions of the interrelationships between the planes. After he identified the Known Planes, the physical worlds such as Azeroth and Draenor, the untamed realm of the Elemental Plane, the madness of the Twisting Nether, and the nothingness of the Great Dark Beyond — Khadgar spent two chapters speculating about their possible arrangement in "a larger world of worlds, a great cosmos."