Emmerich has completed the script for two sequels to the 1996 sci-fi - tentatively titled ID Forever Part I and ID Forever Part II - with co-writer Dean Devlin.
The Amazing Spider-Man's James Vanderbilt has now been handed the script for a rewrite, Emmerich told Entertainment Weekly.
Speaking about the overall plot of the sequels, he said: "The humans knew that one day the aliens would come back. And they know that the only way you can really travel in space is through wormholes. So for the aliens, it could take two or three weeks, but for us that's 20 or 25 years."
He continued: "It's a changed world. It's like parallel history. [Humans] have harnessed all this alien technology. We don't know how to duplicate it because it's organically-grown technology, but we know how