"Castle" Season 8 will be returning this fall specifically on September 21 and fans are excited about what the upcoming season will be about. Due to this, Stana Katic, the actress who plays the role of Detective Kate Beckett, teases that this season will be tackling the unknown noting that the upcoming episodes will be a nail-biter.

According to Realty Today, "Castle" Season 8 will still see Nathan Fillion's Rick Castle and Stana Katic's Kate Beckett although it remains to be unknown if the romantic relationship between the two will still progress or if it will come to a halt. Many fans are saying that the fate of the relationship of the two will be bitter sweet as a new character will be introduced and it is a female character named Hayley who will be spending a lot of time with Castle.

Katic then talked about the upcoming season being a nail-biter as she tweeted a statement about the show on her Twitter account. She shared, "Had a great mtg w @AlexiHawley & @OldManWinter14 about S8! (Nail-biter) Love #Castle cast&crew. Looking forward to playing together again." This does not give away anything but fans are reading between the lines noting that there might be big changes for the Casket tandem this upcoming season.

In another report by Carter Matt, the Casket tandem has been mentioned in a blind item noting that a "beloved network show couple" will be breaking up and that it will be pissing of a lot of people. There has been no confirmation if this is what is expected for "Castle" Season 8 but fans are freaking out over the possibility of these rumors being true.

Christian Today also released a statement from "Castle" co-showrunner Alexi Hawley and he was quoted saying that Season 8 will be shaken up a little bit in order to make a really dynamic story. He noted that the Casket tandem "has room to have movement in it."

"Castle" Season 8 will be premiering this September on ABC. Are you excited to see if the rumors about the all-time favorite couple are true? Sound off below in the comments!