In a move that should surprise no one, Sam Worthington and Zoe Saldana have finalized their deals to appear in all three Avatar sequels, which will be shot back-to-back with Avatar 2 arriving in December of 2016, followed by Avatar 3 in December of 2017 and Avatar 4 in December of 2018.

Director James Cameron previously announced that Stephen Lang, who plays the villain Marine Colonel Quaritch in the original is also coming back. He was the first actor to sign on for the sequels. As his character dies at the end of the 2010 sci-fi epic, its anybody's guess how James Cameron and Josh Friedman, who is writing the second installment, plan to resurrect him for this continuing story. Duo Rick Jaffa and Amanda Silver are penning the third installment, while Shane Salerno is tackling the climatic chapter of this saga on his own. All writers will be collaborating on the overall arc of the entire storyline.

Plot details are being kept under wraps for the time being. The franchise will of course return to Pandora. It is also known that Jake Sully and Neytiri, the two characters played by Sam Worthington and Zoe Saldana, will have kids.

James Cameron had this to say about the sequels.

"Jake Sully is a rare combination of passion, strength, street smarts and soul, which requires a lot from an actor. Sam brought to the role a combination of sensitivity, vulnerability and strength. Zoe captured every aspect of the character I envisioned, bringing to Neytiri a mix of delicacy, fierceness and incredible physicality. I am beyond pleased they'll be returning with us to Pandora."

James Cameron will produce the sequels alongside his partner Jon Landau for Lightstorm Entertainment.