20 Things You Didn't Know About Star Trek: The Motion Picture (1979)
19. Elements Of A Roddenberry Script Called "Star Trek II" (AKA "The God Thing") Ended Up In The Movie
Starting in the mid-seventies, there were several attempts to revive Star Trek, some for the silver screen and some for the smaller one, and bits and pieces of those attempts ended up in the final film.
In 1975, Gene Roddenberry wrote a feature script titled simply Star Trek II—but which fandom calls “The God Thing.” This story is the first to introduce a concept which would end up in Star Trek—The Motion Picture: a huge alien “Object” threatening Earth that turns out to be, essentially, a great computer.
Several other elements introduced here would appear in virtually every other proposal before ending up in the finished movie: the Enterprise being rebuilt as now the most powerful ship in Starfleet; the old crew being pulled together to confront the Object; and Spock studying with masters on Vulcan in some sort of remote monastery.
(Roddenberry later tried to adapt this material into a Star Trek novel for Bantam Books in 1976-77, at one point enlisting the help of Star Trek actor Walter Koenig to work on the manuscript, but the novel was never completed. Star Trek novelist Michael Jan Friedman was brought on board by Pocket Books to try adapting the novel again in the early 1990s, but despite cover artwork for the novel being completed by artist Keith Birdsong, the project did not get very far and was ultimately cancelled.)