'Castle' season 8 will premiere with a bang. As expected, there will be some major changes expected to happen in upcoming season. One of which is the possible breakup between the two main cast members-Rick and Kate. A new female character is reportedly joining the show that could shake things between the couple. But, Nathan Fillion revealed that there is nothing to worry about.

After it was reported that Terence Paul Winter and Alexi Hawley step in as the new co-showrunners of the popular ABC series, a creative reboot or safe to say "creative shake-up" is expected to happen in 'Castle' season 8. IBTimes noted that this shake up will cause major trouble for the beloved characters-Rick and Kate.

It was previously reported by The Hollywood Reporter that Toks Olagundoye will be the actress playing the role of Hayley, the new face who in Season 8. She has been described as this quick-witted and free-spirited former Scotland Yard police officer who has turned into a security specialist. But more than this, she is expected to bring some big changes for the show, especially with Rick and Kate's relationship.

These changes will be scary for fans. But for the new co-showrunners, these changes could mean great story.

In an interview with TVLine, actor Nathan Fillion assures fans that there is nothing to worry about. The actor points out that this will be for the betterment of the show. And it's all part of moving on.

"In order for a show to continue and move forward, things have to change and things have changed over the years for these two. It's simply another change, and it's going to continue to be great. It's all part of smoving forward and not boring [anyone] with what happened last season," Fillion said.

Are the showrunners planning to have an unhappy ending for Rick and Kate? What can you say about the possible breakup? Share us your thoughts below for 'Castle' Season 8 latest updates.