Stana Katic is leaving 'Castle'
IN PHOTO: Stana Katic poses with the award she won for favorite dramatic TV actress for her role in the series "Castle" at the 2014 People's Choice Awards in Los Angeles, California January 8, 2014. REUTERS/Kevork Djansezian

Castle Season 6, Episode 18, titled "The Way of the Ninja" airs Mar. 17 on ABC. There is no new episode this week. Stana Katic, meanwhile, shares some behind-the-scenes photos taken during filming of "In the Belly of the Beast." After the beast, the Caskett couple deals with a ninja. Some fans could use a 2-week breather for that.

Spoiler alert: This feature contains spoilers on Castle Season 6 on ABC. If you are not up-to-date, read at your own risk.

In Castle Season 6, Episode 18, Stana Katic's Kate Beckett is upset. Rick Castle (Nathan Fillion) "makes out" with a geisha. Is the Caskett wedding still on? (Shippers would safely bet is still is.)

It seems the geisha encounter is all part of NYPD's investigation into a murder case, in which "a Japanese ballet dancer is inexplicably murdered," according to Castle Season 6 spoilers. A ninja assassin seems involved, and it looks like Beckett and Castle are the same ninja's next targets.

Arden Cho of "Teen Wolf" guest stars in this new episode, Castle 6x18.

Castle Season 6, Episode 18 follows a landmark episode. "In the Belly of the Beast" marks the return of Senator William Bracken (Jack Coleman). Fans are aware Bracken is coming back this season, but not as "Lazarus." There could be more surprises as the series is fast approaching its season finale.

Stana Katic shared some BTS photos on Twitter. Here is a still photo of the torture aka basement set, and here is Stana giggling during rehearsal. Finally, here is Lazarus himself with Kate Beckett, all warm and friendly in the rain.

Meanwhile, for those wondering about the Castle-Beckett wedding plans, all is well so far. Wedding dress, ready. Wedding song, chosen. Click here for Stana Katic's wedding thoughts on Castle Season 6.

Fans should not worry about Rick's geisha encounter. He has been in some compromising positions before, but Beckett would always get it, anyway. Watch the Castle Season 6, Episode 18 sneak peek video below.

More TV Guide and Spoiler Features

'Castle' Season 6, Episode 16 Spoilers; Stana Katic Teases Next New Episode - 'In the Belly of the Beast' [Watch Promo Videos]
'Bates Motel' Season 2 Spoilers: Norman Bates in Miss Watson's Murder Mystery, Bradley Disappears After [SPOILERS]
'How I Met Your Mother' Season 9 Spoilers: Ted Dies, Mother Dies in Fan Theories; Finale Clues, Answers on 'Daisy' [Watch Promo Video]

Watch: Castle Season 6, Episode 18 ("The Way of the Ninja") ABC Promo Video on YouTube