Castle star Stana Katic has revealed that the upcoming eighth season of the ABC procedural will be a "nail-biter".

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Katic, who plays Kate Beckett on Castle, recently tweeted about having a meeting with new show runners Alexi Hawley and Terence Paul Winter about season 8.

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The tweet was retweeted and favorited by thousands of users. The mention of season 8 being a "nail-biter" certainly has Castle fans intrigued. Obviously this could mean anything, but it could tie into what some fans are speculating to be a huge moment for the show.

The eighth season will feature the introduction of a security specialist named Hayley who will be spending a lot of time with Castle (Nathan Fillion). Some fans are guessing that their professional interaction may lead to something more.

This is especially possible if it ties in with the blind item TVLine recently posted. The blind item says that a couple on a one-hour series will be breaking up, and the producers know that it will anger fans. That couple could end up being Castle and Beckett who only got married as early as last season.

This speculation partly stems from the new Castle show runners claiming they want to "shake things up" in season 8. A Castle-Beckett breakup would certain shake things up.

Producers have not confirmed that the blind item in question is about Castle and Beckett, though that hasn't stopped fans from theorizing.

Castle season 8 is set to premiere Monday, Sept. 21 at 10 p.m. ET/PT on ABC.