Stalburg Underground

Stalburg Underground is a mysterious cult present in Stalburg with an unknown agenda involving homeless people in Stalburg, and The Machine.

History
The foundation of the cult is unclear, Andrew Herts is credited with the creation of The Machine, with the assistance of "seven masked men", Herts may of been the founder of the cult, or his creation may have motivated the worship of The Machine. The cult's affiliation with white masks, and using Hert's death date as a code may put the founding of the cult as early as 1989.

The earliest modern record of urban legends regarding the existence of Stalburg Underground date to November 9th, 2014, but are likely to date back even further. A newspaper article published by The Stalburg Times suggests the cult is ever-present within the Underground City, although what they do in the city is unclear, speculation in the aforementioned article guesses that the cult may run the city itself, or capture homeless people to work as slaves in a psychoactive mushroom farm. All circulations of the story however, include that Stalburg Underground shelters homeless people for some purpose, and no one looking for admittance into their city has ever returned.

A note left by a homeless person in isle1 provides exposition that their cult is based off of another older urban legend, and members wear white masks, perhaps similar to the mask worn by Mörkö. Discarded white masks of the same design can be found in various places in Stalburg. The cult worships a "savage underground god", possibly Mörkö itself, or the UGU, bearing the title of the "god of the underground".

The cult was involved in the pursuit of a young girl, Elo and her family, who were trying to enter, or attempted to escape the underground city. Elo left behind several drawings that suggest she was willingly escorted by Mörkö to the underground city.

INFRA and Open Sewer
There are notes in INFRA which show the extent of Stalburg Underground's influence in Stalburg.

Many homeless people have been reported missing in Obenseuer, and Elo's hideouts can be visited to show they've been looking for Elo and her family. If the Turnip City Metro is accessed in tenements, and Mark abandons his job to try to access the Underground City, he will be incapacitated and captured by Stalburg Underground, leading to the secret ending. A scene plays in which a man in a diving suit attempts to interrogate Mark, who is unresponsive to any of questions. After deeming he is "unfit for manual labor", they sentence him to be executed via The Machine, ending the game.

The man in the diving suit is a prominent member, a drawing of him was scribbled over the warning left in Elo's hideout, albeit with angelic wings. His distinct outfit is also present in a book published by Silvia H. Raven, "The Tunnel of Water Trees". The manner in which he addresses Mark, as well as know his personal information insinuates that they've been following Mark and know he was supposed to go to the Blackrock Nuclear Powerplant.

Their logo is a drawing of a clenched fist, graffiti of which is also found in disused Bergmann tunnels in metroride, as well as in the Deekula 4B apartment complex in Open Sewer, a female member of Stalburg Underground can be talked to in this tenement, but will not admit the player to the door which she guards no matter the dialogue option.

Trivia

 * The alternative name for The Machine, "The Headless Raven", may put Raven Research Institute as an opposing organization to Stalburg Underground, but their relationship if any, is obscure.