The Silver Mirrors, or Suellk Siver Mirrors, are teleportation devices invented by the Creation Creed of the Suellk empire. They were built to traverse the great distances between the important holdings of the empire. After they gained a foothold on a moon or world, one would be brought in and used for moving supplies and people from one Silver Mirror to another. During the First Suellk Invasion, a Silver Mirror was used by the Suellk in their invasion of Ghífthauk. As they gained territory from the githyanki and githzerai, a void transport and its escort would transport another Silver Mirror to Ráglauth.
The Silver Mirrors were made inside the cavity of a colossal living primordial buried beneath Penumbra. This crystal primordial is Axinite. He still lives, and where his heart used to be are the crystal forges used to create Silver Mirrors and other relics. The crystal forges of this area are called the Axinite Forges. They were the fabrication area for the tetrahedron shaped Silver Mirrors.
The illithids of Suellk have a dark and secretive history, and across the illithid society of the multiverse, one even darker than preying on worlds and subjugating them. When the eight illithid city-states of Ráglauth began to run out of humanoids, their "cattle", their cities fell into disrepair, and their economies shrunk. They were were looking at a bleak future where their civilization on the moon Ráglauth comes to an end. As a result, the city-states warred with each other for the dwindling population of cattle. The far-thinking illithids of Penumbra, the Thinker Creed, 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 cattle in-breeding had drastically reduced their birth rates and health. One in four born, also lacked mental facilities to survive on their own. The Creation Creed was tasked with finding a way off Ráglauth. Based on the Thinker Creed's calculations, that great planet in their night sky, the world Ghífthauk, had a 75.4592% probability of having a good-sized humanoid population. Another specialized group, the Creation Society, were informed by their elder brain that to travel the great distance to Ghífthauk required a great pool of psychic energy. The Thinkers were quick to realize what their elder brain was getting at, they must capture an elder brain and use it to power the teleporation. The host must be kept alive and do to the innate teleportive power of elder brains, it must be imprisoned. The Builder Creed set to creating the devices to hold the captured elder brain, while the War Creed took Penumbra's soldiers to war. Penumbra's army was able to capture five elder brains, the other two two died in the attempt.
The elder brain lies at the heart of illithid community. The rule of an elder brain varies by locale, with some being despotic and ruling the affairs of the illithids like a tyrant, but 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"
The Silver Mirrors are powered by the psychic energy of imprisoned elder brains. The mirrors are made of crystal taken from what was the heart of the primordial Axinite. To use them, a creature with psionic potential or psionics briefly merges with the psionic consciousness of the elder brain. They expend their psionic pool and are then teleported to another Silver Mirror. The other Silver Mirrors can be seen like looking through at a picture, and one only has to focus on the desired Silver Mirror and they will be teleported along with anything they are carrying or pulling.
In the Incarsabec Rebellion, the githyanki and githzerai used the Silver Mirrors to teleport to the Astral Sea. They did this without using a Silver Mirror on the other side. How they did this remained a mystery for hundreds of years after they left their home world. Two centuries after the rebellion, dromite explorers from Svirlido found a couple Silver Mirrors in the surface ruins of Incarsabec and one other place. After much experimentation, they learned how to use them and eventually made contact with the Deep Six, the Giff League, and other peoples of Asteraoth.
One of the dromite heading up the research on the Silver Mirrors wrote in his journal of how the Silver Mirrors were used one way by the Suellk and another way by the githyanki, githzerai and now us.
Find others, and know of that what comes for you. I will have my revenge for this eternal imprisonment.
- Penematic, of Svirlido - "Conversation with the Elder of Silver Mirror #3"