If you know the book then move on, but the idea is there is another city within the city, hence the name, but you are not allowed to see the other city, However, we are never given the facts, how or why etc, you just have to believe that you cannot see. Very well directed and the original thought by the author must be appreciated, this is granted, but when push comes to shove the ending is just a very bad murder/mystery. The actors and crew did a great job of producing something that needed to be left on paper.
