[[Duergar]] have been stealing crystals. [[Crystal Thefts]] The can turn invisible [[Footsteps]] and some can grow large. The group discovers their [[Duergar Outpost]] in [[Session 10]] and questions one of their number. Searching for [[Chardilin crystals]] for their [[King Xardorok]] Crystal can be powerful to store or enhance magic. Crystal that is useful in magic can be excavated from special ore but normally it is created. They want to rule IWD. On questioning the prisoner says "[[Deep Duerra]] will curse my family and our souls if I help you. She saved us from [[Illithids]]." We discuss releasing the captive to negotiate our way in. They have a strong resistance to magic (advantage on saving throws).