Beacons in the Dark

Beacons in the Dark is a side quest in Dragon Age: Inquisition.

Acquisition
The quest is acquired upon activation of one of the beacons in the Fallow Mire.

Walkthrough
As the Inquisitor activates the first beacon, two terror demons and several undead attack and must be defeated. The party then remarks there may be others nearby. Activate all four of them, one at a time, and defeat the enemies that spawn to complete the quest.