Aside from the impending career change, it seems like Castle and Beckett's marriage will be facing more hurdles when "Castle" season 8 airs on ABC. 

Newly appointed series co-showrunner Alexi Hawley recently shared a little teaser with the Entertainment Weekly. According to Hawley, things will be slightly different for Rick Castle (Nathan Fillion) and Kate Beckett (Stana Katic) in the show's eighth season.

"Going into season 8, it feels like it's time to shake things up a little bit," Hawley shared. 

At the end of season 7, Beckett was contemplating on a career change when she was offered to run for the New York State Senate. Does this mean that the show will now be focusing on political issues instead of crime investigation? This could be what Hawley was referring to when he mentioned that there will be several changes in the new season. 

"We just want to get in there and try to tell some really dynamic stories," the new series co-showrunner stated. 

If Beckett will choose to run for a government office, she might have to spend more time away from her husband to campaign for the election, which would undoubtedly affect the couple's relationship. 

In a separate interview for TV Line, Hawley said that they still have to come up with a more detailed plan about Castle and Beckett's marriage for the upcoming season. However, he believes that the pair still has a lot of things to improve in their relationship. 

Meanwhile, CarterMatt said that a new and more ruthless villain will be introduced. Since Jerry Tyson (Michael Mosley) is already dead and William Bracken (Jack Coleman) is unlikely to cause trouble any time soon, it seems like a new antagonist will surface to make Castle and Beckett's life miserable. 

As of the moment, the official air date of "Castle" season 8 is still unannounced by ABC.