Alright, humans start a massive fucking war on Pandora, turn that into a 3 hour movie (imagine the end of the first one, but lasts a lot longer) then for the third movie (and hopefully the last one) have the Na'vi invade the shit out of Earth, get brutally wiped out and end the movie with every human on Earth laughing in an evil manner. Because us humans are evil scum and the Na'vi are peaceful, all knowing and loving.