Take the door out to a broken ledge. Jump off the ledge to land next to a new obelisk and magic portal. Explore side alcoves next to the obelisk for another Deathstone corpse and a sack of gold. Follow the passage around until it leads to a door.
The next room is a long rectangle. On the near side, a vat of the silvery liquid called "Sleg" tempts anyone to taste its wanton power. Be forewarned, though: A single sip will forever change your fate and put you on a dark path that will destroy Caddoc's and E'lara's friendship. If you do drink the Sleg, you become nearly invulnerable and your damage increases to fearsome levels. As you enter the room, Wargar of all kinds flood the far side. You'll have to deal with Wargar Guardians, Warriors, Archers, Scorchers, and Zealots.
Move at all times. You can't seek cover for long; reinforcements pour in behind you, too, so cover doesn't protect you well. If you dance around the room, constantly firing at targets or slicing them as you glide by, Wargar by Wargar you will thin the horde. As tempting as the Sleg may be, it's possible to destroy all the foes with some patience, skill, and lots of arrows. When the very last Wargar falls, the portcullis at the room's far end rises and you can exit down the new corridor.
The corridor leads to the temple of the Queen of Darkness. Below you, the Wargar feed the Queen of Darkness a large vat of Sleg. Before the Wargar can think about feeding the prisoners to their Queen, too, it's time to jump into action.