Cameron could work in Weaver return
Sigourney Weaver could be set to reprise her role in the Avatar sequels, despite her character dying in the original.
James Cameron has said time travel and flashbacks could be a part of the forthcoming follow-ups, which would allow the actress to return as Grace.
"Have you ever heard of non-linear storytelling? A lot happens on that planet before she shows up, and before Jake shows up to join her," he told Vulture.
"She's there for 15 years ahead of time. I don't know, but I wouldn't jump to conclusions.
"Here's the deal: when you have a science-fiction series, a science-fiction franchise, you're never dead, unless your DNA is expunged from the universe. And then there's always time travel!"
He added: "And I've already said way too much about Avatar 2 and 3 here and there, but people piece it together like those voice cameos and tell the whole story!"
James assured the film's fans he was focusing on the sequels, saying: "My next films are Avatar 2 and 3. So there's nothing else, not for the next five years."
Details about the next Avatar outing, set for release in December 2014 with the third film to follow in 2015, are being kept under wraps but it is thought to head to the depths of Pandora's oceans.