This past week, James Cameron joined Arnold Schwarzenegger for a 30th anniversary screening of the original 1984 Terminator. While speaking about the event alongside producer Gale Anne Hurd, the director reveals he was the one that came up with a reasonable way to have Arnold Schwarzenegger reprise his role as a T-800 in Terminator Genisys.

James Cameron explains that he gave the idea directly to Terminator Genisys producer David Ellison because he wanted to see Arnold Schwarzenegger return, and he knew how that was going to be possible.

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"I wasn't interested in producing it or working on it actively, but I did want to put in a good word for Arnold. I pointed out that the outer covering (of the Terminator) was actually not synthetic, that it was organic and therefore could age. You could theoretically have a Terminator that was sent back in time, missed his target, and ended up just kind of living on in society. Because he is a learning computer and has a brain as a central processor he could actually become more human as he went along without getting discovered."

This is the idea that will fuel the story behind Terminator Genisys, though not much more is known about the plot. The movie is being considered a reboot-sequel hybrid, and will deal with time travel in a manner that disrupts the events seen in the original movie, causing a wormhole of sorts where the fate of John Conner is radically different from the original series.

Laeta Kalogridis, who wrote Battle Angel for James Cameron and was an executive producer on Avatar, is behind the Terminator Genisys screenplay and did allow Cameron to read it, but the series creator has no comment.

"It's not my problem, that's the beauty of it. It's like being a grandparent and the kids come over then you can send them back. I think the chain's been broken by the films in between. When I walked away from it I had to do it with the sense that I can't invest in this emotionally anymore. If it's not good, it doesn't really bother me personally."