Sacrificial Gates of Segrummar

Sacrificial Gates of Segrummar is a side quest in the The Descent DLC for Dragon Age: Inquisition.

"There are a number of sacrificial gates in the Deep Roads that can only be opened with bloodstained ancient gears. Valta's stone sense is leading her in other directions, but there must be something important behind these gates if someone took the trouble to lock them."

Acquisition
Approach the first sacrificial gate, located beyond the first rune-warded gate in the Darkspawn Warrens.

Walkthrough
There are nine sacrificial doors scattered throughout the Deep Roads. While most are optional, some need to opened in order to progress the main quest.

First gate: (Main)
Find 3 bloodstained ancient gears scattered around the area. Once the gears are installed, a note will appear. Pull the lever to open the door.

Second gate: (Main)
The gate is located in a hallway southwest of the first lift in the Ruins of Heidrun Thaig (3rd level). Find 3 bloodstained ancient gears and open the gate to reveal a chamber with another door. Pull the lever beside the door to open the way forward in The Descent quest.

Third gate: (Optional)
This gate is located across from the second gate. Install X bloodstained ancient gears and a note will appear.

Fourth gate: (Optional)
Located within the northern region of the Darkspawn Warrens (2nd level), the gate can only be reached after completing Deep Roads Expeditions: Heidrun Thaig Upper Bridge.

Sixth gate: (Optional)
Found inside the chamber through the second rune gate, during the "Reclaiming the Thaig" section of The Descent quest.

Eighth gate: (Optional)
Located beyond the second gate in the Ruins of Heidrun Thaig. Requires 4 gears to open. can be found inside the chamber, as well as an entry from Kolg's Journal.