There one day where I did the Elder Blood quest 2 times.At first I doing it like normal but then after around 8 hours I came back to her to buy Scroll of Pangs and I realized that the quest is available for some reason....the room I join is 4982 but the next day when I about to try it didn't work ever again.This happen before they change the require item for the Void Highlord quest..
This maybe just some spaghetti code in the game