Last week, we learned that Avatar 4 has been put on the back burner while 2 and 3 are going to be shooting back-to-back once James Cameron is done writing the scripts. Now, we know why. According to Cameron, the fourth movie is going to be a prequel.

That pronouncement by James Cameron saying he's in the Avatar business and nothing else appears to be bunk. “I'm in the Avatar business. Period. That's it. I'm making Avatar 2, Avatar 3, maybe Avatar 4 … And anything I can't say in that area, I want to say through documentaries,” Cameron told the NY Times back in May.

Previously, James Cameron raised up the possibility of a fourth Avatar movie in an interview with the NY Times in May; and then, in June, Sigourney Weaver revealed that she's doing Avatar 2, 3, and 4 back-to-back-to-back, pretty much confirming the fourth movi

We know James Cameron is currently working Avatar 2 and 3, and he is planning to shoot the two movies back-to-back when he's done writing the script. What we didn't know is that he's doing the fourth movie at the same time as well. According to Sigourney Weaver, Cameron will shoot all three movies back-to-back this fall, and she'll appear in all three sequels.