The Six Families made a deal with the Anvarrid invaders. In return for leaving their Fortresses untouched the psychics of the Families would become warriors to guard the Anvarrid. They would share their technology and give up their individual languages. The Families lied and rather than share technology that could be misused they hid it. Also, one promising engineer in each generation was designated the Oathbreaker and taught the language of the Fortress so they could communicate with it. Then the Horn Family discovers a man freezing to death on a glacier within sight of the abandoned Salonen Fortress. A man with no memory, probably a spy sent by a hostile empire, of pure Salonen DNA, and with an instinctive knowledge of engineering. Killing him and burying Salonen would be the safe choice. Or the Horn might risk their independence, the Treaty, and their way of life to recall the technology of the founders and bring Salonen back to life.
J. Kathleen Cheney
The Families in their underground fortresses have little interest in the world above, although they did offer aid to the first Larossan refugees who came to their lands due to their ancient mandate to preserve humanity. When the Anvarrid invaders eventually conquered Larossa they chose to negotiate with them rather than fight and risk the last six fortresses built by the Founders. In exchange for being mostly independent they vowed to give up their secret languages and technologies and spend their first three years as adults guarding the Anvarrid nobility. They make exceptional guards due to the high number of psychics, called sensitives, among them and the mental discipline required by anyone living with empaths. An uneasy peace has now existed between these three cultures for almost two centuries.