In order to write the story line of the first two film, a complex back story was created in order to connect everything together. So much material was created that it became the screenplay for this film.
This is the final film in series and ends with a huge cliffhanger. Originally there was the possibility of returning to the series with a fifth film at some point in the future, however it is highly unlikely there will ever be another film. The fifth film would have gone in a different direction with new characters and cast that would have branched off the cliffhanger.
Originally the running time was 2 hours and 40 minutes. Many scenes were cut including side stories in order to shorten it and give it a better flow.