Pathfinder Adventure Path: Lord of the Black Sands (Extinction Curse 5 of 6)

On the hunt for a life-giving aeon orb far below the surface world, the heroes venture into a blighted Darklands waste known as the Vault of the Black Desert. Facing off against lurking, vampire-like urdefhan and even stranger subterranean beasts, the heroes track the lost artifact to an enclave of undead dark elves in the twisted city at the vault's blackened heart, where they must confront the malevolent mummy who strives to become the desert's eternal sovereign!