AvatarWith production expected to get underway on Avatar 2, 3, and 4 later this year, casting deals are now being finalised, and amongst the first to be announced to return are Sam Worthington and Zoe Saldana.

The duo will be reprising their leading roles for all three sequels, Fox has announced, joining Stephen Lang, who was the first cast member to officially sign on to return.

James Cameron is set to shoot the next three films back to back, with production predominantly expected to take place out in New Zealand.

Plot details are naturally being kept under wraps for the time being, but THR‘s report notes that Worthington and Saldana’s on-screen characters will have children in the sequel.

And with Lang’s Colonel Quaritch and Sigourney Weaver’s Dr. Grace Augustine killed in the original movie, and both set to return, it’s going to be interesting to see how their characters are resurrected for the first in the trio of upcoming Avatar sequels.

Last summer, Cameron signed a quartet of screenwriters for the next three instalments in the franchise, with Josh Friedman penning Avatar 2, Rick Jaffa and Amanda Silver penning Avatar 3, and Shane Salerno penning Avatar 4.

Avatar 2 is expected to hit cinemas in December 2016, with Avatar 3 and Avatar 4 following in December 2017 and December 2018. The original movie is of course the highest-grossing of all time, taking almost $2.8bn at the box office, and it will be interesting to see how close the sequels come to matching, or unthinkably even beating, the bar Cameron raised first time around.