Solved
The Descent -- Second Rune-Warded Gate BUG
Playing through the DLC a second time, and I've encountered a game-breaking bug at the Darkspawn nest. After pulling the lever to open the gate, I see the scene where shrieks are mobilizing, but then the game decides to fade to black and show the loading icon. I hear combat going on in the background, but the screen never returns to normal and I have no control over the Inquisitor.
http://hastebin.com/zenivepoqi.tex
EDIT: The screen returns to normal after the party's A.I has killed the Shrieks. It takes a while though, and the bug is very disconcerting.
Weird solution: the "stuck on black" problem doesn't seem to appear if I go from using 4xMSAA to using 2xMSAA. Increasing the anti-aliasing after the Shriek scene works fine.
