The episode 21 of “Castle” Season 7, titled “In Plane Sight,” saw Rick Castle and Alexis solving a murder mystery on a plane, with the help of Kate Beckett on the ground. The two were flying to London for Castle’s meeting with mystery writers at Sherlock Holmes society. Here is what happened in episode 21:

Recap of “Castle” Season 7 Episode 21, “In Plane Sight”

The OceanicAir plane is shaking and Castle looks nervous. He tells Alexis that he does not like turbulence. To keep his mind off the possible turbulent scenarios, Castle goes through his itinerary. Alexis tells him that she has her own plans and would not be there to hear him speak to his fellow mystery writers. She will be meeting her friends at a pub. Castle is disappointed to hear that. Alexis reminds him that she is not twelve and they do not need to be attached to the hip. This conversation ends when there is a video call from Beckett. When she asks if everything is all right, Alexis tells her that it is just the turbulence.

Soon afterwards, Castle finds out that it is not just turbulence that he has to deal with. The captain informs him that the air marshal Kyle Ford has gone missing and with him unaccounted for, Castle is the closest to the law-enforcement that they have. For Castle, this is a cause for concern.

Ford’s body is found stuffed in a case in the luggage area. The gun on him is missing. Beckett tells Castle that he can find the culprit while he is worried about his daughter and other passengers’ safety. Alexis joins her father and tells him that she will help in the investigation. She inspects the body, with Lanie helping her via Skype. Alexis discovers that the killer is left-handed.

Meanwhile, Castle goes through a video shot by a gay couple on the plane. He can see Ford keeping an eye on one of the passengers. He is Isadore Baldon, though Beckett soon informs Castle that the man is an imposter and he is on the no-flying list. The real name of this passenger is Aiman Haddad. He is a Syrian student and an ISIS sympathiser. This hints at a possible terrorist attack.

Haddad is arrested and Castle interrogates him. The former tells him that he is not a terrorist. He is flying on a stolen passport because he has to go to Syria to see his mother who has pancreatic cancer. He says that he is on the no-flying list because of his stupid cousin who has joined ISIS. Castle does not believe his story but there is no evidence against him. Haddad’s bag does not have the missing gun and also there are no explosives in it. Haddad tells Castle that he saw Ford sending many texts from his phone, which turns out to be his second phone. It is also found in the luggage area.

Castle finds that there are texts on the phone that threaten to take down the phone. By asking passengers to fill a migration form, Castle finds the identity of a left-handed passenger, with a motive to kill Ford. She is the former executive of OceanicAir, Marilyn Singer. She holds a grudge against the airline and recently she lost a case against them. The missing gun is found in her bag and also the phone that was used to send the threatening texts.

Singer, however, denies that the gun belongs to her. She is shocked to learn that Ford is dead and she tells Castle that the air marshal was her boyfriend. She thought that he was cheating on her. Both Castle and Alexis are not convinced that Singer is the killer. Castle feels that someone may have set her up.

This someone might be German businessman Victor Deitrich. Beckett and team find out that an amount close to $10,000 was transferred to Ford’s bank account by this businessman. Deitrich, too, has nothing to do with Ford's murder. He had paid Ford for the security of $13 million watch on the wrist of a courier who is also travelling on the same plane.

This courier wakes up from a deep sleep and it looks like he was drugged. Castle discovers that the watch on him is not the real one. Someone has stolen the $13 million watch. Castle suspects that the person who carried out the heist must have known about the passengers’ manifest. He believes that it is an inside job.

It turns out to be an inside job. One of the flight attendants, Debbie, points a gun at Castle, seeing that she is going to get caught. Debbie, who has worked with the airline for 30 years, committed this crime after the airline eliminated her pension. She had no plans to kill anyone. Alexis convinces her to lower the gun and surrender.

Castle is proud of his daughter. Alexis tells him that she will be there at the Sherlock Holmes society, as she does not mind being attached to the hip. Father and daughter hug each other. And Beckett keeps a watch on the plane online. She lets out a huge sigh of relief when she sees that the plane has landed, safely, at Heathrow Airport.

For your comments/feedback, you may contact the writer at a.shrivastava@IBTimes.com.au.

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