A beacon stone is an ovoid-cut blue dragonstone, specially attuned to the Keysong siren of a Blackmoor military base or facility. Normally, they merely function as maintenance and service Specialty AIs, coordinating service of hardware and upkeep of a facility and its compliment of vehicles, as well as the garrisoned flights shrikes and choirs of sirens.
It has all the properties of a normal blue dragonstone, with the exception of one extraordinary ability: the Mind Bridge.
A Keysong siren may call upon a beacon stone to bore through the thoughtshare matrix, and directly touch the Progenitor’s mind. Once there, she can select three Intelligence-based skills to receive a one-time bonus of +20 to the next roll required of each of those skills. This reflects a direct glimpse of the Progenitor’s keen insight and precognitive abilities.
While using the Mind Bridge, the Keysong siren’s effective casting level is doubled if she casts spells dealing with Divination or Enchantment, or those with the [air] or [mind-affecting] descriptor. Any such spells return as if uncast when the Mind Bridge effect ends.
Such power does not come without a price. The use of the Mind Bridge subsumes the Keysong siren’s personality, and a battle of wills between the bearer of the stone and the Progenitor’s Master Imprint ensues. Even if the Keysong siren manages to fend off the Progenitor’s influence, the conflict could leave her contaminated with the Imperial Princess’ madness.