Director James Cameron's plans for three consecutive sequels to his box office behemoth Avatar were so ambitious that he pushed them all forward by a year apiece. Avatar 2 is now slated to hit theaters in December 2017, followed by Avatar 3 in 2018 and Avatar 4 in 2019. Now we have new insight into why these delays may have happened, with composer James Horner revealing that the writer-director actually has scripts for four sequels, which he is now trying to condense into three movies.

"Right now Jim has four sequels, script wise. And he's trying to make it into three. And that is where, I think, his effort is going right now. To keep it to three sequels. Because he's got so much going on how do you keep it from expanding into a fifth movie, total. And he'll get that sorted out."

The composer also shed some light on the story for Avatar 2, which, as we previously reported, will largely be set underwater.

"I don't know what Jim's vision will be for how he might portray the various places that are in Avatar 2. A lot of it will take place underwater, which is a completely different environment. I've seen some of his stuff, and it's stunning. All I can say is you've never seen that before, and you know, just from Jim's previous work, how much he's stretching himself, to make something he's never done before. That is what he's doing. He's always pushing the envelope, and he's always expecting everybody who works for him, to do the same thing."

The director enlisted the help of several new writers to work on the sequel scripts with him. Rick Jaffa and Amanda Silver (Rise of the Planet of the Apes) are writing Avatar 2, with Josh Friedman (War of the Worlds) working on Avatar 3 and Shane Salerno writing Avatar 4. This is the first we're hearing about a fifth Avatar script, although it isn't known if James Cameron wrote this himself, or if he brought some of the aforementioned writers to work on Avatar 5. However, it seems that the filmmaker is adamant about making just three sequels, so we'll have to wait and see what happens.

Production is expected to start later this year, with all three movies expected to be shot back-to-back. Do you think there should be a fifth Avatar movie? Or do you think three is already too much? Let us know what you think below, and stay tuned for more on the Avatar sequels.