The Caldera Question

The mystery at the Emberwaste's heart: what did the Vallen Imperium find in the Emberthrone's caldera that made them build the Cindervault, and then seal it from the outside?

Every faction in the waste has a different answer. The Scorch Seekers believe the caldera holds an Old Work working older than the Sundering — still doing something, not just sitting ruined. The Far College believes it is a structural fault that must stay sealed, nothing more mystical than bad rock. The Ashwalkers believe the mountain asked to be left alone and the Imperium didn't listen carefully enough. The answer is inside the vault.