It seems that when James Cameron isn't actively making "Avatar" movies, he's thinking about "Avatar" movies. As the filmmaker admitted in an interview with ScreenRant, he wouldn't allow his co-screenwriters, Rick Jaffa and Amanda Silver, to begin work on "Avatar: The Way of Water" without first reading a massive 800-page tome explaining the mythos and backstory of his sci-fi universe. He has already finished a great deal of work on third and fourth "Avatar" films as well, working with a team...