Chris Pine and Chris Hemsworth may not be part of Star Trek 4 after all. Paramount rebooted Star Trek for the big screen in 2009 with the help of J.J. Abrams. He helmed two installments for them, and set them up for years of success with a great cast, led by Chris Pine, Zachary Quinto, and Zoe Saldana. When Abrams left to do Star Wars: The Force Awakens, Justin Lin stepped in to direct Star Trek Beyond, but it was met with a lowered return at the box office. Still, plans to continue the franchise aren't slowing down, as a fourth film is in the works.

The next installment was set to bring Chris Hemsworth back as George Kirk, the father to Pine's James T. Kirk. How exactly they were going to explain his non-death remained to be seen - although a time-traveling story was possible - but Star Trek 4 looked ready to add one of Hollywood's biggest names to its main cast. Unfortunately, now the sequel may happen without either Chris.

THR reports Pine and Hemsworth's contract negotiations for Star Trek 4 have collapsed, leaving their involvement up in the air. The disputes come over money, where Pine and Hemsworth are looking to be paid as major stars thanks to their respective DC and MCU roles. Paramount wants the stars to take slight pay cuts to help with the film's budget. There's still a chance that all sides could reconvene and work deals out, but as of right now, both Pine and Hemsworth will most likely not be in Star Trek 4.

While not being able to bring back Pine and Hemsworth would typically signal a total collapse of a project, this report indicates that Paramount is not planning to halt development of Star Trek 4. Recasting could be in the franchise's future, but to what extent isn't clear. After Paramount closed deals with Pine and Hemsworth to return, they were then going to lock down franchise regulars Saldana, Quinto, Karl Urban, Simon Pegg and John Cho. If Pine and Hemsworth are both out, some of the other cast members could follow suit, or take on larger roles themselves if the studio doesn't opt to recast, and instead just removes the Kirks from the franchise.

This isn't a great position for the film to currently be in, especially for first time director S.J. Clarkson. This is still early, so Trekkies shouldn't panic just yet that the Kelvin timeline is falling apart entirely. Should Paramount come back to Pine and Hemsworth with contract offers meeting their quotes, then they can quickly rejoin the fray. Since the chemistry of the cast is one of Star Trek's biggest strengths, it would be beneficial for all parties to find a way to resolve this. And with the film possibly filming early next year, a solution will need to be found quickly.

Additionally, if Paramount isn't looking to delay Star Trek 4 after this stumble, it likely means that Quentin Tarantino's possible film won't suddenly become a bigger priority as a result of this shake-up. Both films are in development, but all signs point to Star Trek 4 happening before Tarantino's. However, if the fourth film can't get a good chunk of the cast to return, a combination of the projects could conceivably happen. Many have been skeptical that Tarantino will ever actually direct a Star Trek film, and since Clarkson's dealt with more adult material in the past with Jessica Jones, she could possibly take command of that hypothetical combo project if Star Trek 4 ultimately doesn't happen.