(SPOILERS) Secrets of the dwarves act 4 bugged

[Dr.Fumetastic]

After dealing with Isbeil Justinia plain simply doesn't spawn in the room behind the doomsday device despite the fact she was supposed to and my characters even referring to Justinia "being able to handle herself well" in regards to the dead dwarfes.
EDIT: I loaded an earlier save and apparantly the Queen does spawn but simply despawns if you leave the area without talking to her. Even after doing that however, the quest log seems bugged as the game doesn't acknowledge me talking to her and still wants me to confront her even though Beasts quest updates.

[Krauthaus]

Some guy tells you that she might be in klemms mansion, take a look in the upper floor.

[NOMAD]

Krau is right - She can be found in the guest room in Klemm's mansion - But I also noticed the same issue Dr. Fumetastic is having. When I reloaded a quick save, she came barging out of the door on her own (like a scripted interaction event) and I could talk to her. In another save, she just never appears in there.

[Majere]

I had a related bug which might as well go here, though it straddles the line between 'bug' and 'amusing anecdote'.

Whilst I was dealing with Isbeil and her little friends some joker managed to set off one of the crates of Deathfog right next to the door which leads to the place Justinia is being held, to the extent I could only get to it by using Teleport. So Her Royal Shortness comes boiling out of her cell and I decided to spare her, only for her to run off through the door immediately after the conversation and blunder straight into the fog and drop stone dead. You could call it poetic justice, but I'm not taking the blame for it later if it comes up...