The Trials of Mistledale
This dwarven village of stone-and-thatch cottages has a secret. The “deep mine” on the outskirts of town isnt a mine at all, but a passage into the Underdark. It allows the dwarves of Glen to trade with their fellows as far away as the Great Rift, via an amazing underdark tunnel called the Long Road that runs south under the entire length of the Sea of Fallen Stars.
The Glenfolk have used the Deep Mine to reconnect with their brothers and escape the dangers of the infernal invaders, who tried to take over Glen.