From the introduction: Long ago, when this world was but a cooling orb, its gravity bound to it a dreadful companion- a sphere of crystal which soon came to be known as the Mad Moon. That simple sphere was filled with a baleful radiance, a stark reminder of warring heavens to all who beheld it. To call the Mad Moon simply that was a mistake, for it was in fact a prison built to hold two opposing intelligences when the universe was still in its infancy, the handiwork of Primordials who had tired of their constant warring and bound them into a singular body supposed to fall through and for infinity as punishment. That it came to rest around our world was nothing but luck.