I explored all main halls and I was clean all (about 4 - small areas in deep halls). Now I in room (main halls) with stairs up to halls of stone and down to main halls. I have two questions:
1. who is in magical prison in north side on main halls and how I can make him free
2. this down stairs get me to all deep halls or have do something else to make way free.
In the magical prison is a Dark Naga called Preybelish I think. just go away first time afetr you talked to him and next time you will arrive there (some minutes later) he will open and attack you.