How to unlock: After completing the What Yet Lingers and Avvar Allies quests.
Quest giver: Svara Sun-Hair (M31,10)
Talk to Svara (M31,10) in Avvar camp. Next, reach the point shown on the map and walk along the river, passing the checkpoints on your way.
The path leads to the ruins in the north (M31,16) which are guarded by Jaws of Hakkon. Get inside and eliminate all the enemies. Next, approach the small camp and wait for Kenric. After the cutscene, go to the northern part of the stronghold.
In the middle, you will find a puzzle (M31,16a). When you solve it, you will be able to go through the door on the right and on the left, to collect valuable treasures. You need to press the plates in such way, that the combination looks exactly like the one in front of the door.
To do that, follow the order described below:
- The switch in the center and four on the outside (in whatever order), but not the corner ones.
- Switches on the outside, along with the corner ones.
If you want to reset the switches, use the nearby lever. To continue the quest, go up the stairs.
You will notice a green magic barrier, which you should destroy using the veil fire located on top of the wall (when standing in front of the barrier, turn left and use the wooden scaffolding to get to the top of the wall) (M31,16b). Once you get rid of the barrier, go inside. You will find another veil fire. Using it, examine the two runes in the corners of the room (M31,[16c,16d]).
Leave the chamber now and go on to of, to the place where the veil fire was. You will find a lever. Use it to activate the spire (you will see green lightnings).
Approach the spire (M31,16e) and use the lever. A short cut-scene will show you the direction towards the next trail marker. Head in this direction until you reach a large gate of a hold in the eastern part of the map (M31,16f). After you activate the last spire, the barrier in the gate will be destroyed. Return to Svara Sun-Hair (M31,10). In the next quest, you will be assaulting the gate.