Black Mountain Mines, Levels 1-2
1 - Ore Golem / Rock Sprite If you attack an ore golem or a rock sprite with most melee weapons, you'll damage the weapon. So you're better off using ranged weapons, spells, or your bare hands to kill them.
2 - Seething Mass Seething masses are just like ore golems, except they'll also damage your armor if they hit you. So plan ahead and remove your armor first.
3 - Dead Thief On his corpse you'll find a couple scrolls and another note from "G.L."
4 - Forge There are three barrels in the forge. In them you'll find mechanized gauntlets, eye gear, and a schematic for the pyrotechnic bow.
A. Exit to the world map.
B. Exit between level 1 and level 2.
C. Exit to level 3.
D. Exit to level 4.
Black Mountain Mines, Levels 3-4
1 - Chest with Kathorn Crystals Most kathorn crystals appear randomly, but here's a place where you're guaranteed to find them. You should hang onto a couple because you might need them in an upcoming quest (to get into the Wheel Clan's home).
2 - Gudmund Ore Bender Gudmund is a little crazy -- he's the one who put all the traps on this level of the mines -- and you won't learn a lot from him, other than comments about "despair" and "betrayers."
But behind Gudmund you'll find the Pillar of Truth, carved by Gudmund when he was saner. You'll learn that the Black Mountain Clan was banished to the Isle of Despair for sharing technology with humans (that is, for showing Gilbert Bates the steam engine), and that Loghaire, the king of the dwarves, and a group of elves were responsible for the banishment.
The meeting with Gudmund is the main reason for visiting the Black Mountain Mines. If you're working for Gilbert Bates, then when you return to him he'll introduce you to Edward Teach, a ship captain who will take you to the Isle of Despair. If you worked for Appleby or killed Bates, then you'll still need to go to Teach, but you'll have to pay him money to take you to the Isle of Despair.
3 - Garden
You can find a lot of organic components here.
4 - Chest with Power Axe
Exits: A. Exit to level 1.