The quest "Here Lies the Abyss" culminates in a massive assault on Adamant Fortress, a mid-game turning point where you must confront the corrupted Grey Wardens. After navigating the initial battlements with help from Cullen’s forces, your objective is to find Warden-Commander Clarel. Along the way, search the battlements for the "Redened" note and other codex entries to uncover Corypheus's influence. You will face waves of Pride demons and Venatori mages; prioritize disrupting the rifts scattered across the courtyard to halt demon reinforcements. Keep an eye out for the 'Agony' unique mace hidden in a chest near the lower ramparts before proceeding to the final confrontation.
The climax of this location presents two of the most significant choices in the game. After the battle moves into the Fade, you must decide which companion—either Hawke or the Warden ally (Loghain, Stroud, or Alistair)—will remain behind to face the Nightmare demon, effectively sacrificing them. Upon returning to the physical world at Adamant, you must then choose the fate of the Grey Wardens: exile them from Orlais or conscript them into the Inquisition. Exiling them removes their presence from your war table but prevents future corruption, while recruiting them provides significant military strength but may cause disapproval from certain companions like Solas.