Star Trek 4 was all set to bring back Chris Hemsworth as Kirk’s father, and then it fell apart. Hemsworth and Chris Pine, who plays Kirk in the rebooted film franchise, both walked away from the project, putting the future of Star Trek 4 in serious doubt. Salary negotiations were cited as the reasoning behind Hemsworth and Pine jumping ship. But now, Hemsworth has revealed another reason: he wasn’t happy with the script.

J.J. Abrams’s 2009 Star Trek reboot opened with the birth of Captain Kirk during a big space battle aboard the USS Kelvin. During the battle, baby Kirk and his mother escape, but his father George Kirk, played by Chris Hemsworth, dies. Star Trek was released before Hemsworth became a much bigger star thanks to the Marvel Cinematic Universe, and in the years that followed, J.J. Abrams came up with a pretty neat idea: what if Hemsworth came back for a sequel? While the full specifics have yet to be released, the pitch involved some sort of time travel element causing the now-adult Kirk, played by Chris Pine, teaming up with his father for a big adventure.

This concept was going to be implemented for Star Trek 4, and originally, Hemsworth was game. “I’ve spoken to J.J. Abrams, and he has an amazing pitch on the whole thing,” the actor said in 2017. By 2018, Star Trek 4 pre-production was ramping up. S.J. Clarkson was hired to direct. The movie’s future seemed like a done deal. And then it all went to hell. By summer 2018, both Hemsworth and Pine quit. The reason given: salary negotiations.

But there was apparently more to the story than we realized. In a new interview with Variety, the actor reveals he had some issues with the script:

He turned down the next “Star Trek” sequel because he wasn’t sold on the script. “I didn’t feel like we landed on a reason to revisit that yet,” he reveals. “I didn’t want to be underwhelmed by what I was going to bring to the table.”

Hemsworth is being a little vague here, so it’s not clear if he didn’t like the script as a whole, or if he just wasn’t happy with the way the story brought his dead character back to life. No matter what the case, the actor did not feel comfortable signing on. It’s possible the production could’ve continued with a new actor taking Hemsworth’s place, but Pine’s departure was the final nail in the coffin, since he’s the lead of the franchise.

Now it’s unclear if we’ll ever get a Star Trek 4. If we do, I’m just going to go out on a limb and say Hemsworth won’t be a part of it.