Version 6.3.16

This quest is started from an item (Book: The Powers Below (5352)) dropped by mobs in the Master's Glaive and probably in the base of the Cave Mushrooms cave.

Twilight Disciples (2338) and Twilight Thugs (2339) - Wowhead has some coordinates.

As far as I can see, there are no coordinates/clue as to the item's occurrence in your database.

The problem with this quest is, that it would flood the map with icons since the NPCs have a lot of spawns. We have yet to implement a nice way to show such quests.

Surely you do not need an icon for each occurrence, just representative ones in each location? Wholly/Grail use one icon at each corner of the Master's Grave and one in the cave in the north. At least the NPCs should be mentioned in the text description on the search parts.