I'm in the (?) endgame and I've managed to rescue everyone except Amber & Sister Katherine- neither of which I can find. I have checked all the rooms that I know of, except the maze & extensions of the vent system (which is metal, don't you know). I suspect someone (probably Amber- her bedroom is right next door) is in the downstairs bathroom, which is locked. I don't have any keys left and I can't speak to her. The walkthrough stops short of this point. How do I proceed?
Never mind. On the third run-through, I found that I had missed a room and it resolved itself.