But it made a plot bunny bite me.
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Setting: Black Mesa (Forge World)
Plot: The forge world Black Mesa is home to a secretive Adeptus Mechanicus sect known as the Lambda Sector, which revolves around the maintenance and study of the ruins of a Standard Template Constructor complex from the Dark Age of Technology built into the craggy ground of the planet. The STC complex was badly savaged during the Age of Strife, but the ruggedness of its construction and the stable, seismically dead world of Black Mesa helped preserve enough of it for lucrative study. Several Standard Template Constructs also survived, but most of these were in the form of simple hand tools that have survived in working order. These tools are used both as objects of study and as holy relics used in the Lambda Sect's veneration rituals.
The most jealously guarded prize in the complex, however, is an advanced piece of orange-grey-and-black carapace cobbled together from the remains of several such carapace suits scattered all over the planet. Such was the damage they sustained during the Age of Strife that only one such suit was pieced together in working order (although there are rumours of at least two more). This suit is the centrepiece of Lambda Sect's worship rituals.
In an unusual practice for the Adeptus Mechanicus, one of the number of menials about to be inducted as tech-priests is chosen to have no enhancements at all—not mechanical or biological. This unenhanced tech-priest to be is given the honour of donning the Sacred Carapace during Lambda Sect rituals. It is believed that an unaltered candidate is chose to express the oldest form of machine communing with man, although the myth-lost origins may have been a little more practical—heavily modified tech-priests and their extensions and mechadendrites just would not fit into the Carapace. This is a highly coveted position, especially since such a prized piece of technology actually has a machine spirit that whispers gently to the wearer while he or she has it on. Although the whispers are not understood since they are spoken in a long-dead tongue from the Dark Age of Technology, it is still considered a great blessing by the Omnissiah to have one of their number regularly commune with such an ancient and holy machine spirit.
The Chosen for the Carapace is selected from several cogitators running the names of possible candidates at random until one name emerges from all the cogitators in unison. This is believed to be the purest expression of the Omnissiah's intent, and it can take a good long while. Some candidates have been chosen centuries after their unaltered predecessor passed away. The latest Chosen, one Gordonius Freeman, has caused quite as stir due to the small gap—less than two decades—between his Choosing and the Choosing of his predecessor, Wallacite Breen. This has caused some whispers about Breen having become less worthy to the Omnissiah somehow, but few would dare say such things in the open about one of the Chosen. Still, Breen harbours resentment towards Freeman because of this.
Lastly, Black Mesa's ancient STC complex also harbours the fragments of an ancient portal system that would make Warp travel far, far safer. The extremely incomplete nature of the STC plans for this portal systems have made any serious attempt at heir recreation highly forbidden, especially given their Warp-related nature. However, recent movements within in the Mechanicus, as well as secret backing from a radical Inquisitor with a strange speech pattern, have loosened these restrictions. By the time of the next major Lambda Sect ritual, coinciding with the arrival of said Inquisitor, they are ready . . .