Somebody (Timbecile?) said that the original plan was that after you released the kids, they should follow you back through the teleport to Frosgard. This was another part of the game that wasn't fully implemented, and all you need to do to complete the quest is to free them. They can then find their own way back.Incidentally, the last time I did this quest, when I entered his throne room, I spotted Yanmir just entering the passage I had intended to use. I was able to do a quick about-turn and take a short cut through his throne room. Then I found the secret door, shot out the supports, and was quite happily decimating the ice lobbers when the cutscene showed Yanmir falling through the floor.
