In Valindra's tower you appear at the dracolich ritual room, before you even go to Thay. Even if the party has advanced to the final boss. Same thing in Karrundax: someone can be at the boss room, but any new arrivals will spawn at the very beginning of the dungeon.
EDIT: Originally post was about VT only. Changed to be more generic, since this appears to be a bug with all dungeons (and probably skirmishes, but I've not experienced this to be certain).
Comments
Great way to waste everyone's time.