You can get Brumbledon's key without any violence (see Durnore section) and complete one of the main Crux of Fire-related quests for 1000xp if you do it that way, but you might also be able to pick the high-level lock here as well. Either way: You can complete the main quest to reclaim the Crux of Fire without killing anyone in the mines— though ensuring your own survival won't be quite as easy.
|The Hammerlorne Key from Brumbleton's locked chest in Durnore opens this lock.|
The Hammerlorne Grand Hall
As soon as you step inside the Hammerlorne Grand Hall, you'll be trespassing on sacred dwarven ground, and all the Dwarven Miners you encounter will be hostile to you. (At any times when stealth isn't an option, we still found the miners susceptible to higher-level castings of Sparkling Wonder for at least a few turns, which is enough to keep them at bay long enough to get past, or keep hostile dwarven miners from blocking narrow pathways or entrances.) There are also a number of large black Bonebiter rats in the Grand Hall chambers, but they're also easy to scare away with the same spell.
In order to get to the Crux of Fire, you'll need to go to the narrow upper central passage (running northwest by southeast, but not the wider passage running all the way to the far southeastern main entrance to the Grand Hall) and take the southwestern passage in the middle of it: This will bring you to closed gates with a lever that opens them nearby, but also a locked door you'll need to get past to reach the one-way teleportation pentacle into the mines.
|The Grand Hall and chest containing a security key to enter the teleportation chamber to the mines...|
The Hammerlorne Mines: The Maze
After taking the one-way teleporter into the mines, you'll find yourself in a maze that the dwarves probably built to confound invaders.
|There is a hidden door through a section of illusionary wall directly between these two torches.|
|This stairwell descends to the second deeper levels of the Hammerlorne complex...|
Having reached this level, you'll find yourself in the northwest facing the passage leading into the Dwarven Tombs, where you'll arouse the wrath of ancient Dwarven Spirits, and also encounter significant numbers of marauding skeletons and skeleton archers.
A Puzzle of Gates and Levers
You'll have to overcome the obstacles of a series of locked gates (and floor traps) by finding levers in various parts of the tombs, and throwing them to figure out which gate they open elsewhere.
Fortunately, if you make a mistake, manipulating the levers and backtracking to see exactly which was opened should eventually work (unlike many unforgiving dungeon crawlers of yesteryear, which would often trap you for throwing a single lever out of sequence).
|The entrance to the treasure room blow open with a powder keg...|
You'll reach this treasure room by taking the southwest passage from the junction. Even if you're very scrupulous and don't want to steal anything from the Dwarven Tombs (other than the mandatory Crux of Fire, which you'll find deeper in the mines), the treasure room you can find at the end of this passage contains one of the four bells you'd need to return to Lockston Hall's archives in order to claim 30,000 nonviolent experience points later on. Since you're already causing offense by your presence in the mines, you may want to consider doing this (though you certainly can still win a smooth pacifist run with no kills without relying on the extra 30,000 xp).
If you want to get into the treasure room: You'll need to retrieve the black powder cave from the cave chamber at the end of the northeast passage (from the junction), and bring it back to blow open the wall. One of the three chests is a combination chest, and there is a plaque above the wall that will give you a clue to figure out the puzzle.
|The stairway descending to the deepest level of the mines, where you'll find the Crux of Fire...|
Hammerlorne (third level): The Mines & Dwarven Vaults
You'll arrive here at the northeast end of a long passage leading to another four way junction. You'll find some miscellaneous chambers by taking the southeast passage, but aren't sure there's anything crucial to find there.
|The four-way junction near the starting point of the vault and mine level of Hammerlorne...|
|The Dwarven Gold Reserves (which you can view, but not steal).|
When you take the southwest passage, you'll pass a teleportation square that can take you back to the upper levels, but if you want to head onward toward the Crux of Fire, you can just continue past this and throw a lever that opens a gateway into another chamber facing southeast.
The Devilmander Pit
Before approaching this area, be aware that entering the wider chamber below will trigger an unseen trap releasing hostile Devilmanders, which are faster than most foes, and more difficult to deal with.
|The Devilmander Pit|
There are some traps at the bottom of the next area, after which the path turns northeast, finally pointing you toward the mine caverns that will soon lead you to the Crux of Fire...
The Mine Caverns
At this point you'll finally have reached the mines. There are several side chambers leading into large mine caverns that might contain a few random treasures and black powder kegs, and you can also use these to rest if you need to. (If you happened to be relying on a limited stock of potions but have foraging and alchemy skills to brew more, this might be a good time to forage for more reagents.)
|Teleporting into the inner cavern containing the Crux of Fire|
|The Crux of Fire enshrined on a pedestal.|
|An invisible mage slips past the Dwarven miners who appeared in the mines to attack the thief who stole the Crux...|
After you escape from the mines and Grand Hall, you'll finally be able to leave and return the Crux of Fire to Korren at the secret Gulid of Crius Vindica on the Forsaken Coast, in order to continue the main questline.
As an aside: You may hear a rumor later on (from dwarves in Eschalon: Book III) referring to Lord Brumbleton's wrath over the theft of the Crux and invasion of the Hammerlorne Mines. However, Brumbleton won't ever seem to suspect your player character of being the culprit, and he'll remain civil to you at Durnore (assuming he didn't catch you burgling his own chambers). Whether you feel guilty about your trespasses or not, you have at least now passed one of the game's more formidable dungeons without killing anyone or anything inside!