1 - Trapped Dwarves Talk to Erland Iron Heart (the dwarf technologist) and learn about the mistake he made that allowed all the zombies to appear. If you've been to the Wheel Clan and have the quest from Thrayne Iron Heart, you can deliver his message now and earn 6400 experience. Regardless, Erland will give you the key to the storage room (#3).
2 - Hard-to-See Chest Inside you can find the muscle maker schematic.
3 - Storage Room You should find mithril ore and dwarven ore inside.
4 - Passage to the Laboratory Inside you'll face a level 30 bludgeoner and two putrid walkers. The bludgeoner is big and hits hard, but it's also slow, and so it shouldn't give you any problems. Once it's dead, loot the table on the western side of the lab. Inside you'll find Kerghan's journal, a necromizer schematic, a ring of dark magicks, and a medallion of dark magicks.
Exits: A. Exit to the world map.