I'm still having trouble getting through this quest. If I open the door to the room with the chest, things explode and send the character opening the door to the far side of the inn(!?). If I go through the mostly-burned door, the room next to the person I need to rescue is engulfed before I can get my characters into the room. Then I try and talk to the guy calling for help, and the game won't interact with him. The camera/mouse seem to think I'm pointing at the lower floor, because anything I click on sends my characters back out of the room and running downstairs. The pathing in this is INFURIATING.
I know there's a second person in the building, but I have no idea where they are because it's been a YEAR since I've been able to successfully complete this quest.
I've tried most of the suggestions above, and nothing seems to work. This quest is so busted.