For about five minutes, Ryan Gosling was going to star in the next big sci-fi movie from Oscar-winning directors the Daniels. But the Project Hail Mary and Star Wars: Starfighter star, who sometimes can seem like the living embodiment of Everything Everywhere All at Once, soon dropped out. It didn’t take long to find a replacement: Matt Damon—no stranger to sci-fi himself—is now aboard. Even more excitingly, we have our first plot details with this news. The Hollywood Reporter writes that the as-yet untitled film is locked in to shoot this summer in Los Angeles. That’s actually a big reason why Gosling and the Daniels parted ways. The actor requested script revisions, and there just wasn’t enough time in the tight schedule to accommodate them. The movie’s plot revolves around “global warming, time travel, as well as a possible superhero angle. And there are two timelines, one set in the 1980s and one set in the present day. The protagonists of the story are teens … at least in the 1980s-set timeline.”

So that’s a twist: the role that Gosling was to play, which has since gone to Damon, isn’t the lead, it’s the father of one of the teens. THR explains that it’s a “substantial” role but still more of a supporting part, and “Gosling, after initially agreeing, thought it should be larger and asked for script changes, according to sources,” the trade wrote. “[The] Daniels did not necessarily disagree, but there was a larger issue. The project […] has to start production by the end of summer or early fall because it has received a California tax credit.”