The Maps of Myrist
The Erudites had a problem. Some of their people were beginning to practice the dark, corrupt art of necromancy. The Erudites branded these misguided mages as Heretics and drove them forth from the city of Erudin.
In the ensuing battle resulting from this banishment, magic clashed at a titanic level. At the climax of the battle, the earth itself was ripped asunder blasting a series of craters deep into the wounded firmament. The greatest of these was called The Hole.
Both sides were dismayed and frightened by the devastation they had unleashed. Separated by the crater and weary beyond belief, both sides retired from the field. The Erudites returned to their home and the Heretics retreated to the caverns uncovered during the creation of The Hole. Decimated by the battle, the Heretics practiced the ways of secrecy and slowly faded from the memory of the Erudites.
They may have been forgotten, but the Heretics were not inactive. Deep in The Hole they built the hidden city of Paineel.
For many years they practiced their dark art, perfecting their mastery and exploring the underground passages of The Hole. It was during these explorations that they came across the Vault of Living Stone. This artifact is said to have been created by Brell Serilis to seal the passageway he had opened from the Plane of Underfoot to Norrath. It was through this passageway that he had brought his creations. Once he had finished his seeding, he put the Vault of Living Stone in place. The vault was a magical construct designed to perpetually repair itself and keep Norrath safe from Lord Yael's forces and the more vicious denizens of the Plane of Underfoot.