Cavern of Dead Dragon Age II Guide
Last update: 11 May 2016
The quest giver: Jansen [The Bone Pit]
Step 1: Talk to Jansen
You can start completing this quest after coming to the [Bone Pit] location and clicking on Jansen #1 (M31, 7). It will be possible some time after completing the secondary quest Cave Crawling connected with eliminating the spiders from the mines. This time, Jansen tells you about the scourge of undead #2.
Step 2: Eliminate undead
Do not enter the northern passage and that's because in this quest you'll deal with another part of mines. So head east and locate a passage (M31, 10) leading to the [Bone Pit - Bone Pit Mines] #1 (M69, 1) location. Once you're finding yourself in a new place #2 you will have to decide how to reach a room with mini-boss.
You can go to the northern #1 (M69, 2) or eastern #2 (M69, 3) room. In both cases you'll run into small groups of corpses and skeleton archers but you should not have much trouble with eliminating them. It is worth noting that in the northern room a trigger trap is located, which can cause you some problems if you do not manage to disarm it.
If you go through the northern room then after fights head east #1. And if you have chosen an eastern room, then after fights go east and then head north #2.
Regardless of path you have chosen, you need to reach the central hall. Once you're there attack immediately the arcane horror #1 (M69, 4). Kill it as fast as possible, because there is also hostile revenant in this area #2. After eliminating main opponents start killing weaker monsters.
When the battle is over, I suggest taking a look into nearby chests #1, where you can find valuable items, a maul Persuasion or Helm of the Emerald Knights among other things. Now you can return to the [Bone Pit] location and inform Jansen (M31, 7) and rest of miners that they can go back to work #2.