Yeah, this quest is a bit borked right now:

• The introductory quest text screen has a no/yes option at the bottom with no indication of what you're answering.  I presume it's whether to accept the quest, but that's not really clear at all.
• The game crashed to desktop on me the first time I entered the Demon's Tomb.  (On reload, it did not crash).
• Is Eldorad correct that you're supposed to be answering a riddle/question?  It had seemed to me that I was already congratulated and was being asked to select a reward (which then wasn't being given).  I never saw any question/riddle to answer.

I took it as a choice of awards too, either wisdom (exp) or tomb (marks a place where some item is)  But I can see it also being answers to a riddle