Oliver is fine, actually. [He takes a quick glance around the lobby, then gestures toward the freight elevator that's the only door of its kind in the lobby.]

That's one of the ways she might've gotten out. A while ago the castle rebuilt itself and in the process I ended up with a freight elevator up to my room. It's the only functional elevator in any of the towers, but it only goes to my room which she is not in.

Otherwise, she would've gone out the front door and down the stairs of the tower.