Soultaker Dagger

The Soultaker Dagger was used by Durlag Trollkiller to capture the soul of powerful demon by the name of ? many years ago. This dagger is a normal dagger, when the properties of the weapon are compared, because it has no special abilities. The dwarf Hurlag in the inn of Ulgoth's Beard requests you to retrieve this dagger from Durlag's Tower in his subquest. This dagger is retrieved when the party reaches the lowest level of the dungeon. When they return to Ulgoth's Beard with the dagger in their possession, the will have an encounter with members of some cult. The party will give the dagger to these cult members or they will successfully steal it from the party.

In-game description
"This dagger weighs heavily in your hands, and is warm to the touch. Merely having it on your person makes you uneasy for some reason. The gem mounted in the hill seems to have some inner light of some sort, though how it can have such illuminations and still be so deathly black at its core, you do not know."