Okay ... so I'm one delve away from earning my "Lower Craglorn Cave Dweller" achievement. All I need to do is clear Balamath. Unfortunately, I can only find one of the 4 bosses that are supposedly in this delve. I beat a large Frost Atronach (Nomeg Z....) in the lower portion of a library. I'm also supposed to beat Fire Mage Linin, Frost Mage Porcia, and Storm Mage Iribia. I have already completed a quest called "Elemental Army" which someone told me is associated with this delve. There is one door that I see other players entering at will but I am not permitted to enter for some reason. I'm wondering if these bosses are behind that door and the game is glitching on me. I've looked all over the place for these bosses everywhere else and can't find them. I'm I screwed or is there a secret that I don't know about?