This is a quest that involves the exploration of Durlag's Tower. There are several other side quests that can be initiated and accomplished by exploring the tower. Traveling to Ulgoth's Beard and speaking with these NPCs will help to understand the purpose of each of these respective quests:
- Ike will give you a guided tour for a price.
- Hurgan Stoneblade will ask you to retrieve a family heirloom.
- Therella will ask you to find her missing son.
A full walkthrough for the tower is located here: Durlag's Tower Walkthrough