If you’ve already completed the quest, you’ll need to get back to the Keep of the Eleven Forces, located just south from Shimmerene. This is where the portal to Artaeum is now unlocked. Go through it and head left – west shortly after. You’ll soon reach a part of the compound where a blue light illuminates the entrance to the Traitor’s Vault. Go through it.
Based on the quantity of moldering ruins on Artaeum, once there must have been many more Monks of the Psijic Order than are present today. This hall looks to have been abandoned more recently than most.
In the delve, follow the path to your right at all times. This path will take you to the top floor, and the ruined part of the pathway, where a Bone Colossus defends the Skyshard that is looming over the center of the Traitor’s Vault.
Traitor’s Vault Entrance
Looming over the center of the Traitor’s Vault