Shadowkeep stands in the northern reach of Shyona, well off the roads the council lords keep, and its stone is older than any Shyona town. Nobody living built it and nobody living knows who did. What everyone knows is the dark. The keep and the ground for a quarter-mile around it sit under a shadow the noon sun does not lift, a gloom with weight to it that pools in the lee of the walls and thickens toward the inner court. This is Vulus, the element, shadow worked into the world as a substance and then left there. It is not natural night and it is not the dark of a cave. It is a wound that has not closed.
The cause was a single shaper, generations before the Shyona came north. A dark-shaper of rare depth made the keep their seat and worked the Vulus seam that runs beneath it, drawing more shadow through the membrane than the seam could give without tearing. The seam ruptured. The shaper is gone. Whether killed by the rupture or swallowed by the dark they had called up, no record says, because there is no record and never was. The bleed never sealed. The seam still runs erratic under the keep, strong and unsteady, and that is why the shadow stays.
Things live in it. Generations of birds have learned not to cross the gloom, and the few animals that den in the cold halls have gone pale and wide-eyed, hunting by the sense the dark rewards rather than by sight. Shyona keeps its distance. The council posts no warden and tells no story straighter than stay north of the plains and you will not need to know. What the keep held, what the shaper wanted, and whether anything of either remains in the inner court is exactly the knowledge that died with them.