Necropolis Satellite Mortuus

Small moon orbiting an unnamed dead planet near the star Betelgeuse. The surface of the moon is a barren, blasted landscape.  However, due to advances in Terraform technologies, the interior, which consists of labyrinthine natural catacombs, has been made habitable, though less than comfortable.  With a mean temperature of 51° Celsius (125° F), and the constant hazard of superheated winds spiraling up from the planetary core, only the most steadfast lifeforms take permanent residence there.
Mortuus was used by the Fraternitas Lucis Niger (FLN) as a necropolis for three millenia, until the apostasy of the hyperviolent Schwarzmond Sect (SS) made it prudent to abandon it.  Now, the SS utilize it as a corpse-farm and ritual center.  Because of interior atmospheric conditions, corpses desiccate and mummify quickly, giving the SS access to a veritably limitless source of preserved flesh for use during Totenmond Invocations. A number of flesh, bone, and stone “suspensions” have been erected in some of the larger chambers of the catacombs.  Their exact purpose remains unclear, though they appear to have ritualistic significance.
The SS differ from the FLN in that they actively pursue theological ends explicitly eschatological in nature.  On several occasions, representatives of the SS have hinted that scientists allied with their group have made strides toward the manufacture of a working Doomsday Machine.  Upon detailed study of SS literature, it becomes clear that once such a device is created, the SS intend to detonate it during an elaborate ritual designed to invoke the primordial demon Baal, of whom the SS are singularly dedicated devotees. 
SS doctrine teaches that during the chaos of the universal creation, Baal was imprisoned in the X1vS Night Dimension by his sibling and mortal enemy Azura.  During the long aeons of his imprisonment, Baal has gained immense power through the use of magical ritual and live sacrifice.  The SS believe that the detonation of a Doomsday device will free Baal and allow him entrance to this dimension.  Once crossed over, he will engage Azura in a final conflict, during which Baal will be victorious and usher in the Aeon of Blood.  Because of their sacrifices, the SS believe that Baal will reanimate all souls, over which the SS will rule as Great Masters.
Because of the relative inaccessibility of Mortuus, the SS is able to continue the practice of their Proscribed Theology without much fear of interference.  Recent rumors seem to indicate that the SS has purchased and begun to install a Schwarengeist M-XIIvI Obskuror identical to the one used by the inhabitants of Phallatus.  Covert surveillance of Mortuus by Council agents has noted several visits to the moon by craft registered to Shwarzenwerk Systematisch & C., which seems to confirm the verity of the rumors. This will make Mortuus all but impregnable except by deep-cover stealth or RedLight Transposition.