In the temple at Ust Natha, there this door (left of entrance) other than the egg room that I couldn't enter. Was planning to check it out after finishing the egg sequence but completely forgot and have left the underdark. Did I miss anything special, any good items? And how do I open that door? Thanks.

Welcome to the board!

As I remember, there is no door off to the left. The door straight ahead is the door where the demon summoning occurs, was that it? Off to the left is a lowered platform with a few drow priestesses, I believe. I don't think you missed anything.

(Slaps forehead) You're probably right, must have been the summoning room itself. And thanks for the welcome!