In the depths of interstellar space lurks a living orphan planet. Imortaluese lifeforms feed on geothermal energy and illuminate a fragile biosphere, scarred by a war between the sapient peoples of Immortalu, those who live in the dark, the Shadolings, and those with bioluminescence, the Glolings. A third race, the Greylings have divided themselves between the light and the dark.