Nobody is dead forever in James Cameron's sci-fi universe, so don't expect Sigourney Weaver to be sitting out of "Avatar 2."
"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 explained in an interview with Vulture. "
But that's not his only explanation for how the late Doctor Grace Augustine might return to the "avatar" universe: "Have you ever heard of nonlinear storytelling? A lot happens on that planet before she shows up, and before Jake shows up to join her. She’s there for fifteen years ahead of time."
Check out the rest of today's casting news after the jump!

We already know that
He's getting comfortable behind the camera, but
When you're a 15-year-old kid, your perception of yourself is rarely the same as the way the rest of the world views you. Such is the case with 15-year-old Oliver Tate (
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