The Marcabs were a powerful galactic civilization of human-like beings that existed at the same time as the Ancients of Algol. An oppressive, totalitarian people, they established several outposts in the Beta Persai system before their Confederacy collapsed due to war.
Although the appearance of their dress, architecture and technology is eerily similar to that of 1950s Earth American, albeit much more severe, stark, cold and also monochromatic, they possessed a much higher level of scientific sophistication and mastered the manipulation of psychic energies.
Several of their outposts on Algol survived as extradimensional enclaves. Accessed via armored, bunker like vault doors, these enclaves are notable for the complete absence of any color within the extradimensional space, with everything appearing to be be composed of grays, black and white. Usually these Marcab Enclaves consist of a towering, almost inhuman skyscraper like structure, usually with several shorter wings, surrounded by an endless flat plain of thick, closely cropped turf. It is constantly mid-day in these enclaves, the sky cloudless.
The few remaining Marcabs are usually immensely powerful Mind Wizards with access to powerful technologies. Their servitors are usually robotic or synthetic, although some have been known to abduct outsiders and force them to take part of their "society." It is said that all Marcabs are insane, and that some of them have been warped by psychic energies, mutating into inhuman monstrosities over the aeons. Some insist that certain especially loathsome psychic abominations that lurk in the darkest pits of Algol are descended from such Marcabs.