The Trouble with Darkspawn

The Trouble with Darkspawn is a side quest in Dragon Age: Inquisition.
 * The Venatori, led by Servis, were excavating when they accidentally broke into Darkspawn-infested tunnels. Servis has since fled the vicinity.

Acquisition
The quest is acquired by talking to Knight-Captain Rylen after claiming Griffon Wing Keep.

Walkthrough
The quest will highlight a search area north-west of Griffon Wing Keep, patrolled by Darkspawn troops. Approach the center of this area and a second spot will be highlighted north of the first. In this location, The Inquisitor advance will be stopped by noxious green gas similar to the one encountered in Death Drink Spring (where the War table operation Crossing the Sulphurus Pits was unlocked). Claiming the location, will unlock the War table operation Find the Source of Darkspawn.

Performing the War table operation will update the quest goal (Access the Tevinter ruins), and replace the noxious gases with a raised walkway leading north, to the Prison Ruins. The ruins hold the entrance to Coracavus's North Prisoner Entrance.

Inside Coracavus, the quest objective updates to Investigate the area. At the far end of a long hall, the Inquisitor will find a hole in the Prison's walls, from which Darkspawn must have come through. Energize the hole to seal it, and the quest objective will be updated to Locate those responsible for the excavation.

Once the hole into the Deep Roads is sealed, continue exploring the prison. Beyond the Records Room, the Inquisitor will find a sealed door. The key (Wrapped Prison Key) is found on a corpse nearby, together with A Crumpled Note signed by Servis. Reading the note will update the quest objective to Track down Servis in The Western Approach.

Beyond the door, a short hall leads to the South Hall, where the Inquisitor will find a Giant. The gate beyond him leads to the South Entrance of Coracavus, and the location where Echo Back Canyon Camp can be established in The Western Approach.

Servis is found further south, in Echoback Fort, with some more Venatori troops. When defeated, Servis will lie wounded on his back, and the Inquisitor can chose to let him die, or take him to Skyhold alive. In the latter case, Blackwall approves of the decision, and Servis can be judged via the Sit in Judgment quest/feature.