An expansion on the original Tomb of Horrors with plot and explanation. Contains a facsimile of the original adventure. The Dark Intrusion is causing the dead to rise from their graves. This is linked to a being known as the Devourer. Following the trail of Desatysso, a wizard who followed a similar quest, the players must enter the Tomb, and beyond that, the cursed City that Waits and the Fortress of Conclusion.

Book 6, and the conclusion, of the Iron Gods campaign: More than treasure waits within the alien chambers of Silver Mount - here, the greatest of the Iron Gods dwells, preparing for its triumphant emergence after eons of preparation. Having recruited allies from across the land and cowed the brutal rulership of Numeria’s capital city for the time being, the heroes are ready for an expedition into Silver Mount’s mysterious interior. What strange perils from beyond the stars await the PCs within the metal walls of one of Golarion’s most legendary dungeons? In trying to save Numeria, could the heroes be walking right into a trap?

In the aftermath of AD&D Second Edition's "Return to the Tomb of Horrors," the demilich Acererak was thought destroyed. In truth, his spirit lingered and now after eons he schemes once more to achieve divinity. The characters must travel to three extraplanar dungeons, in addition to the remains of the original Tomb, in order to stop this from coming to pass.