The Dwarves of Glorydeep - Act 3 Broken World Story Quest
The Dwarves of Glorydeep is the first Story Quest in Part 3 of the Broken World Expansion Pack. You'll begin this quest immediately after you complete Solanum, the final quest of Act 2. What you need to do for this quest is to defeat the 6 overseers found in the Hall of the Overseers to the east of the Glorydeep Enclave.
While traveling through the Halls of the Overseers you'll come across two Side Quests, Captured Miners and The Explosives Tunnel. Both of these will be given to you by dwarves which you'll pass by while clearing the area. There is only one more Side Quest that takes place in this Act which is Naturalist Ithara's Research (Part 3) and you'll begin the quest as well as complete it the same way you did the previous two parts.
After you've defeated 3 of the overseers and passed the dwarf who gives you The Explosives Tunnel Side Quest you'll come to a big room with all 3 remaining overseers in it (pictured below). Nearby this area you'll also find the switch which you'll need to press to complete The Explosives Tunnel Side Quest. I strongly recommend you do this quest because it'll explode all the towers around this room and you'll get good loot from each destroyed tower.
After taking out the remaining overseers continue east to find Stonepick whom you'll want to speak with to complete the quest. When you complete this quest you'll automatically begin the next and final quest of the Broken World Expansion Pack, The Overmage of the Cinbri.