Tombs of NightFollow

How do I get into the "Tombs of Night"? When I click the door behind the waterfall in Nek it takes me into the instance "The Tombs of Night : A Search for Answers" and the mobs in there won't give me quest updates. Thank you much.

If you are referring to the instance you need for the D'Morte questline, then you will have to complete a set of quests first before you can get there. Finding the four missing scouts I believe is the first one.