Unwanted Legacy Quest
This quest begins automatically, right after you finish the first act and become a royal ruler. You should help Harrim by visiting the old dwarf fortress with him where the trolls made their lair. You’ll need this location in the main story quest of the chapter.
Once you arrive, go inside and come down to the lower level. In this story quest, you should defeat their leader and investigate the anvil which Harrim is going to break to end the quest.