Seeing as Project Mannhauser is highly classified, it is not known what is being done, exactly, at the facility.
Since the addition of the research facility was done following the Dorn incident, a lot of speculation has ensued. Some workers claim to have overheard tech-priests converse about protective measures from what lurks in the Prytaneum, while others speak of highly sensitive weapon-patterns being deciphered and some even consider the Humerus to be nothing less than the first step in rendering the Orbital Station warp-travel capable.

Exallon and the Bor Rebellion
Twenty years ago the shuttle Exallon came within the restricted zone of the Humerus and was escorted to the Castellanus by a detachment of Thunderhawks on duty. The crew of the Exallon was held in the infirmary for questioning many months following their infringement. They all had severe burns on most parts of their bodies and the medical staff could do little to assist the Adeptus Arbites in keeping them at a level of conscience, sufficient to conclude the interrogation. The last one of them passed away after nine days.
A warden of the medical facility, named Karrack Bor, claimed to have seen writings on one of their bodies, which told tales of powerful creatures rewarding worship. Compelled by these tales he began massing followers in the months following the crew’s death by recounting these tales. Exactly three years, three months and three days after the death of the last crewman he led minor revolt in the Prytaneum. The rebels sought access to the Naxes Sector, but armed only with small arms they posed a modest threat to Arbites on call that night-cycle.
Karrack Bor was incinerated by a meltagun at point-blank range and with him died the rebellion. |