Church of the Ancient Dead
"The Church of the Ancient Dead is the 764th biggest religion in the Union and has over 500 Million believers. The CAD members travel at least once to Tomb World to visit the Catacombs and the old temple. Since it is quite a trip they usually do it during Union week when the School year ends and the big School vacation begins, or they come during the end of year school break and so two seasons of Pilgrim visits developed. It gets quite busy around here and then you won't find a free Hotel room anywhere."
Manjeet Singh, Tombword 5050
It grew out of the obsession the Belmac over the remains of an unknown race simply known as the Dead. The Belmac claim that the Dead can still make their wishes known.
The Dead have similar to the Antoo and the Narth tried to make the next step in evolution and make the transition from biological life form to energetic entity. (So far only the Nnnth have managed to do this and only because they had help from the Arth and thus becoming the Narth).
The Dead are stuck between realities / universes and have even less purchase on the Planck Universe and are fading inside Hyperspace