Stana Katic as Kate Beckett and Nathan Fillion as Richard Castle in ABC crime series 'Castle'.Facebook/Castle

"Castle" season 8 is just two weeks away and fans are curious to know the various changes that are going to take place in Richard Castle (Nathan Fillion) and Kate Beckett's (Stana Katic) relationship.

The two-part premiere titled "XY" will mainly revolve around the various challenges faced by the popular onscreen power couple after the detective opts for a career change. It is going to be an action-packed sequence that will place the lead characters on cross roads.

The official synopsis of the first episode reads: "Castle and Beckett are adjusting to Beckett's career change in the action-packed premiere. But things will take an unexpected turn after a call from a mysterious stranger set off an explosive chain of events."

Although the episode description does not have any details about the mysterious stranger, there is a buzz that it could be the corrupt politician Senator William Bracken. It has already been revealed that Jack Coleman will have a powerful return to the show after Katic's character decides to be the new captain.

However, fans of the ABC crime series will have to wait until Monday, 21 September, to meet the mystery person who is creating new problems for the mystery novelist and his lady love. But speculations are rife that Richard will cross the lines to save his partner in the unique two-parter, which will explore the same story from each of their perspectives, first from Castle's side as he searches for Beckett.

Meanwhile, a set of new cast members, including Kelly Rowan, Toks Olagundoye and Sunkrish Bala, will join Fillion and Katic in "Castle" season 8.

While "The O.C" alum Rowan will play the role of a university dean named Carla Feller, "The Walking Dead" actor Bala will portray a high-strung tech analyst with a complicated past. For Olagundoye, it will be a rough journey with Richard as his newly hired security person Hayley Vargas.

ABC will telecast "Castle" season 8 premiere titled "XY" on Monday, 21 September, at 10pm.

Also read