The Silver Mirrors are teleportation devices invented by the Creation Creed; a department of the Suellk Empire. The Silver Mirrors were built to traverse the great distances between the empire's holding - then covering all of the moon Ráglauth. In the First Suellk Invasion (135 HE - 150 HE), the Suellk invasion against the nearby world of Ghífthauk was supplied by way of Silver Mirrors.
Silver Mirrors are made inside the cavity of a colossal living primordial named Axinite. Deep beneath the mind flayer ruin of Penumbra, still alive, He still lives, where his heart used to be is the Axinite Forge. In this area, the tetrahedron shaped Silver Mirrors that supported the Suellk Empire's invasions of other worlds, were forged.
Suellk has a dark and secretive history, one even darker than preying on worlds and subjugating them. When the eight illithid city-states of Ráglauth began to run out of thrall, their "cattle", their cities fell into disrepair, and their economies shrunk. They were looking at a bleak future where their civilization on the moon Ráglauth would end. As a result, the city-states warred with each other for the dwindling population of cattle. Penumbra's far-thinkers, the Psi Intake, knew that even if they were to get all the humanoids from the other city-states, that it would only give them maybe three generations of stock. This was because a millennia of thrall in-breeding had drastically reduced their birth rates and health. One in four born lacked mental facilities to survive on their own. The Creation Creed was tasked with finding a way off Ráglauth. Based on Psi Intake models, that great planet in their night sky, the world Ghífthauk, had a "75.4592%" probability of having a good-sized humanoid population. The Creation Creed were informed by Penumbra's leader, an illithid elder brain that to travel the great distance to Ghífthauk would require a great pool of psychic energy. They soon realized that they must capture an elder brain and use it to power a teleportation. The host must be kept alive, imprisoned in a device to harness its latent psychic energy. While the Creation Creed set to creating a device to hold a captured elder brain, the War Creed took Penumbra's soldiers to war. By the end of the Flayer Wars (1943 LE - 1968 LE), Penumbra had captured five elder brains.
An Elder Brain is the heart of the mind flayer community. The rule of an elder brain varies by locale, some despotic and ruling the affairs of the illithids like a tyrant, while most simply act as consultants, advisors, and, most importantly, the living repository of the community's technology, history, and psionic experience. By imprisoning the elder brains of other illithid communities, the Suellk were in effect committing genocide on them.
- Ushiruk, of the Deep Six, excerpt from his book - "Elder Brains In Chains"
A Silver Mirror is powered by the Psychic energy of an imprisoned elder brain. The mirrors are made of crystal taken from what was the heart of Axinite. There are two to use a Silver Mirror, a creature with psionic potential or psionics, briefly merges with the psionic consciousness of the elder brain. After expending their psionic pool, the traveler is teleported to another Silver Mirror. The second method allows teleportation to a location plotted on a star map. The Silver Mirror is tuned into the location by using sound, with notes plotting to points on a star map. The latter method requires someone highly skilled in music and still poses dangerous; if the notes are off, you may find yourself teleported into the Void.