The Secrets of Cogstone

From publisher blurb: 5th Edition Mini-Dungeon for five characters of levels 9-11 The gnomish tinkerers of Cogstone were once known across the vale for their amazing inventions. Cogstone airships drifted among the clouds and their creations sold in every major city. Centuries have passed and no one knows what happened to the gnomes. They simply vanished. Soon people began to fear what the gnomes might have created in their secretive laboratories. Now only treasure seekers and adventurers dare to enter Cogstone, and most never return.