So Thalia managed to locate Thaddius in the Prism of Light dungeon mining away for gems. She tried a lot of ways to talk with him but he does not seem to respond to any attempts to strike up a conversation (not sure if his keywords are not enabled or if something broke). So she communicated our desire to have him come help us this Saturday with the undead problem. If anyone else figures out how to make him speak, post here please. Good luck.