Castle Season 8 will premiere in back to back episodes on 21 September at ABC and will be directed by Rob Bowman. Faced with the decision to become the team's captain or accept an offer to run the senate candidacy, Kate Beckett is to endure a speculated third wheel to the charming team in ABC's successful crime drama series. Spicing things up will be Toks Olagundoye, an alumna of 'The Neighbor', who will play a witty security specialist named Hayley Vargas. 

Season 7 introduced changes with the development of a political plot and changes will continue in Season 8. Off screen, Terence Paul Winter is co-running the production with Alexi Hawley transitioning changes from Season 7.

In an interview with Nathan Fillion, the actor emphasized that changes are necessary to keep the viewers interested in the show. He also told fans that Rick and Kate will still be a couple but in Season 8, the relationship will be put to a test.

Aside from the addition of Hayley Vargas, another character named Vikram Singh, a tech analyst, who will be played by Sunkrish Bala will join the team in Season 8. Bala is seen in The Walking Dead, Awkward, and Modern Family.

Several reports claimed that Hayley Vargas' presence in Rick and Kate's blissful lovelife will turn the fire down between the two. Vargas' character is described as a smart, strong willed, and independent woman who is initially set to portray as an advisor to Kate and helped her decide which career path to pursue.

Since its premiere in ABC on 9 March 2009, the show has an average viewership of 11.37 million in US.  One of its episode "Boom!" from Season 2 was one of highest audience views with 14.5 million viewers and announced as the highest rated show of ABC in its time slot for 14 years.

Castle Season 8 returns on the small screens starting September 21 on ABC.