Carcasses for Infernal Hounds (Pathfinder)

From publisher blurb: A Pathfinder Mini-Dungeon for 4-6 characters of levels 18-19 The way into this horrific processing center is lost far beneath the world’s surface, where seemingly nothing living exists—so the clink of metal on metal is especially surprising. A side path becomes a worked passage; stairs descend a chain filled corridor bathed in blurry grey light. Suddenly, evil creatures and characters feel fully rested and ready for whatever awaits them. Then the party penetrates an invisible membrane into a wide corridor. What in the world awaits beyond this strange membrane and who stole my ring of wishes!?