Thrjaxia's moon hangs low in the sky, an ever present fixture in the skies along with the multitude of Dross Rifts raining trash down on the planet.
The moon is pock marked with craters and for all intents and purposes looks like any other moon despite how it hangs so unnaturally low in the sky. Despite that it looks like a moon, it is in fact a space ship that has been disguised to look like a one. The ship itself is no longer capable of space travel and the reasons for the ship in disguising itself are now lost to time. The ship's AI called Dharjak has become a god-like entity to the former crew who have become mutated into the ghoulish Moon-Spawn.
Moon-Spawn often raid the surface of Thrjaxia for slaves and junk that they can use to effect the never ending repairs on the decrepit and labyrinth ship. The Moon-Spawn are universally feared on Thrjaxia for being enigmatic raiders. Yet they are not the worst threat to the people of the wasted world below. When the Dross Gates opened the ship was in orbit near the planet. A Dross Rift opened in the engineering section of the ship and the result was disastrous. A gate to a hellish dimension was opened mutating the crew into Moon-Spawn, bestial creatures of low cunning and effectively immortal unless subjected to violence. It also allowed something from the hellscape beyond, a demonic presence, to invade the ship. This demonic force, if it should escape the confines of its imprisonment on the ship would bring dire consequences to the planet below as a wave of demonic creatures would flood into the world. To contain the threat Dharjak has recruited the former crew to gather resources from below to maintain the matrix imprisoning this vile entity.