You know the trend: It started with Harry Potter and the Deathly Hallows. Potterheads were excited and confused to hear that the final movie of the series would be split in to two parts.It hadn’t really been done before (unless you count Kill Bill Volumes 1&2), and nobody really knew what to expect. Little did we know, this trend wasn’t going away anytime soon. It seems that the industry has decided that any film based on a book required more than one movie. But why?