'Castle' Season 7 Episode 21 Spoilers: Someone Points A Gun At Rick Castle [VIDEOS]

[Spoiler Alert: The article contains spoilers from the new episodes of "Castle" Season 7, read at your own risk.]

“In Plane Sight” is the title of episode 21 of “Castle” Season 7. The episode will see Rick Castle (Nathan Fillion) and Alexis (Molly Quinn) travelling to London, sans Kate Beckett (Stana Katic). They will end up investigating a murder mystery at 30,000 feet, with the help of Beckett on the ground.

“As Castle and Alexis travel to London, their routine flight turns deadly when the plane’s Air Marshal is found murdered,” according to the official synopsis of episode 21 of “Castle” Season 7. “With the help of Beckett on the ground, Castle and Alexis race against time to find the killer before he carries out his fateful plan.”

The preview of the episode shows that the air marshal has gone missing and soon afterwards, it is revealed that he has been murdered. Beckett is seen encouraging Castle that he can find the killer, though the latter does not look confident about that. The preview ends on a threatening note, as Castle sees someone pointing a gun at him.

In the sneak peek of “In Plane Sight,” Castle can be seen telling Alexis that he feels that something is not right, seeing two members of the crew talking animatedly and not smiling. He goes to find out what is wrong. The Captain is seen telling him that they can use his assistance. She reveals to him that Kyle Ford, the air marshal, has gone missing. And “right now with the air marshal unaccounted for, you’re the closest thing we have to law enforcement on this plane,” the Captain tells Castle. The latter, however, sees that as a cause for concern.

The next episode, episode 22 of “Castle” Season 7, is the penultimate as well as the 150th episode of the series. Singer Carly Rae Jepsen is guest starring as herself in this episode, titled “Dead From New York." Beckett and Castle will be seen investigating the murder of Sid Ross, the creator of a long-running comedy show, according to the synopsis of the episode. The two will uncover "shocking secrets" related to Sid’s murder.

Meanwhile, US Weekly has reported that Katic has walked down the aisle with beau Kris Brkljac, a business efficiency consultant. According to the actress’ rep., the two have been in a relationship for a long time.