Troth Glenbeard was a dwarf with a mission. And that was destruction.
From there, things happened. And the Irondeeps got a Subterranean-Transport-System-That-Moves-Things-Around-Faster-Than-Equine-Means (aka, in modern-speak, a subway).
A village where everyone goes blind sometime during puberty. What could be causing this? Perhaps something in their diet. Or some malignant gene. How would an entire village where only young childen can see function?