An End to the Suffering

I also had trouble with finding where i turned in this quest.

You actually do not turn the quest in to the skull. You will have to do the quest again. Do not rush out of the instance until you turn it in. You will find the NPC on the stairs after killing Darkmaster Gandling.

I don't know about the above question, but I've had this quest done in my log for like, a year, and today wanted to just turn it in and get rid of it to make space. So I zoned into Scholo, yes I had it on heroic mode, and the skull only offers to let me turn in the other quest he offers, to destroy the tomes. Apparently I cannot turn this quest in to him where he resides just inside the instance? Despite everything on Wowhead here pointing toward the fact that I should be able to?

Is he also in another location, at which location I can turn in the quest? Maybe something like he is at the end in Darkmaster Gandling's room and because I didn't see him there when I did the quest and missed turning it in, now I'd have to run the whole dungeon again just to turn in the last quest from the very end of it? Sigh.

I'm going to assume that's the case as I can't figure out what else the problem might be here. So, yeah, my advice is, when you kill Darkmaster, turn in the damn quest right away, otherwise you're screwed and can't just zone in the front door, turn it in, and leave again. Gotta finish the whole thing again I assume.

I am having the same problem as Heimdallen. Did the quest a few weeks ago. The talking skull is just inside, but the quest is not available to turn in.