Sigourney Weaver and Stephen Lang are apparently going to feature in all all three Avatar sequels, despite both of their characters being emphatically killed off in the first film. Explaining the unlikely casting news for Weaver Director James Cameron said:

“We’re good friends who’ve always worked well together, so it just feels right that she’s coming back for the Avatar sequels. Her character of Grace Augustine, as fans know, died in the first movie, so she’s playing a different and in many ways more challenging character in the upcoming films.”

Cameron also discussed the subject of Lang’s return and potential status as principal villain for the entire franchise in another recent interview:

“Steven was so memorable in the first film, we’re privileged to have him back. I’m not going to say exactly HOW we’re bringing him back, but it’s a science fiction story, after all. His character will evolve into really unexpected places across the arc of our new three-film saga. I really look forward to working with such a gifted actor, who’s also become a good friend.”