Getting the same thing. Saved Alwah, cleared the rest of the temple but didn't have the Rymrgand quest. Whenever I try to go back into it now it's just a black screen with a cursor, crashes if you click anywhere.
EDIT: So after researching a bit, I found this is similar to the Raedric Keep bug that's been going around. Same fix applies, you can find the info here:
http://steamcommunity.com/app/291650/discussions/0/618457398968195247/
To summarize: open your save file (C:/Users/[YOUR USER]/Saved Games/Pillars of Eternity) using 7zip or WinRAR, find AR_1203_Oldsong_Noonfrost.lvl and delete it. This will reset the entire map including NPCs. I've confirmed this fixed my crashing so hopefully it helps.
