Blackpowder Promise - The Cavern
The doors are just stone slabs. You can break them down to open up the new areas, and reach a second area. You’ll hit a new group of Tal-Voshoth, but they should be fairly weak. The area’s also tight, so it won’t be any harder than the ones outside.
Just keep moving. There’s a silverite sample on the left side of the path before the next encounter. When you find the next group of Qunari, you’ll notice that they have an officier with them. You’ll need to grind down the men quickly, and then focus on the officer. Just use your usual tactics to tank the officer and then knock out the others.
There’s just one more group left. You’ll find a Qunari leader in the next one, along with a ton of Tal-Voshoth. This one is a little hard. The leader isn’t actually that tough. Merill actually managed to solo him for about ⅓ of his health on hard, for a quick example. The problem is what happens as you cut through the grunts on the floor. In the third wave, a qunari mage (Saarebas) will spawn. This mage will teleport all over the room, and use a devastating lightning spell that can easily take out your entire team. If you see the ball of lightning form, you’ll have a few seconds to pause and get everyone clear. Otherwise, be ready for a lot of healing.
The leader won’t go down easy either, and the third waves are fairly rough too. Just hang in there.
I actually had to decrease the difficulty to normal to survive (without pulling my hair out). That actually makes it pretty easy, because the mages spells are weakened and it seems much easier to take him out. If you’re having trouble and don’t have a good damage dealer (I hadn't found Isabela yet), just temporarily decrease the difficulty.
Once the leader is dead, you can loot his body for the formula for combustible grenades. Loot the dead, then use the back door to reach the rear exit and leave the area.
You can now go to the Docks and gain access to the Qunari compound by stating your business with Javaris and the Arishok. Negotiations will not go well, so just talk to them for a bit to get your background information, and then beat a hasty retreat. If you press the issue of "future profits", you'll get an extra coin from Javaris.