ity#3600
If you get stuck by being unable to complete a quest, delete the latest .que file(s) and see if it resets the quest.
The quest save files are in My Documents/My Games/Titan Quest/SaveData/Main/[your character name here]/Levels_World_World01.map/[difficulty level where you're having an issue]. Sort these files by "Date Modified" and delete the last one or two. See if this resets the quest for you.