Somewhere in the demonweb is a chunk of the Duchy of Wescott, pulled through by an angry spider queen when the Princess of Wescott reneged on a secret deal made between them. The chunk of stone and dirt once had a small palace upon it which was immediately razed after pulling it through to the demonweb.
Now the only reminder is the roughly 400 foot diameter chunk of stone and dirt entrapped in magical webbing – the ruins upon it are all but obliterated by demons and time. But not far from the ruins is a hole into the rock and dirt face, once natural but then upgraded and modified by a few survivors and defenders of the princess after the destruction of the palace and the death of their ward.
Now the inhabitants of Wescott Hole have no memory of the origins of the name, and all are more demon than human (cambrians, alu-demons, and half-fiends) as they bred with the local stock in order to survive.
But the Prince of Wescott Hole (a blighted half-fiend sorcerer) still has the signet ring of the Duchy, a magical device that is needed to turn away new predations on the prime. And a sage has recently found out where it is.