Kate Beckett (Stana Katic) is spending some time away from her husband Rick Castle (Nathan Fillion) as she embarks on a work-related trip on her own in the upcoming episode of "Castle" season 8.

Beckett previously asked Castle for a break from their marriage after her startling discovery about her mother. She told him that she needs some time alone to deal with the pain. But it does not mean that Castle will let go of their marriage any time soon.

But Castle will be busy helping a friend in need in the upcoming episode of "Castle" season 8.

According to the synopsis for the episode, Castle will be visited by his old friend Detective Ethan Slaughter (Adam Baldwin) to ask for his help in solving a high-profile robbery case.

The official synopsis reads: "Detective Slaughter (guest star Adam Baldwin) returns to enlist Castle's help in solving a high-stakes robbery case. But when a body is found linked to the crime, Slaughter becomes the number one suspect in the heist turned murder, while Castle has to determine whether he's guilty or help to prove he's innocent."

Beckett will not help Castle in this case since she will have to go an official trip, according to series co-showrunner Alexi Hawley. The showrunner told TVLine that she will be "out of town at a meeting for a couple of days, at a work-related function." The episode was shot during when Katic was in Milan.

Fans should expect to see a positive development in Beckett and Castle's marriage in "Castle" season 8 episode 8. In an earlier interview with TVLine, series co-showrunner Terrence Paul Winter said that the episode titled "Mr. & Mrs. Castle" is something to look forward to. "For the fans who right now are going, 'What the heck and Terence and Alexi [Hawley] doing?!,' when they see that episode they'll understand and see what we're going for," Winter teased.

"Castle" season 8 airs Mondays, 10 p.m. EST, on ABC.