Castle & Beckett get an up-close-and-personal view of a "Real Housewives"-esque reality TV series, "The Wives of Wall Street," when they investigate the murder of the show's rising young star. Meanwhile, Castle's attempt to give Beckett a Valentine's Day gift goes horribly wrong.
While investigating the murder of a young woman, Castle and Beckett find evidence that links her death with Senator William H. Bracken (guest star Jack Coleman returns), the man responsible for Beckett's mother's murder. Determined to finally bring Bracken to justice, Beckett soon realizes that things are far more complicated than they seem.
When Beau Randolf, the founder of hit adult video franchise "College Girls Gone Crazy," is murdered, Castle and Beckett are confronted with a lengthy list of husbands, fathers and ex-college girls who all have motive. So to find the killer, they must delve deep into the victim's life, where they find surprises at every turn.
When an up and coming DJ is killed at a pop star's album release party, Beckett and Castle must dive into the raucous world of New York's music industry. Then, when the investigation leads to a troubled teenager, Esposito takes the kid under his wing, hoping to put him on the right track before it's too late.
When a powerful divorce attorney who only represented women is murdered, Castle and Beckett are confronted with a plethora of angry ex-husbands, any one of whom could be the murderer. Meanwhile, Castle's ex-wife (Darby Stanchfield, "Scandal"), Meredith, moves into the loft to take care of Alexis while she recovers from Mono, and to make matters worse, Beckett is also forced to move in while her apartment is being fumigated, causing tension, humor and more than a little awkwardness.
When a bearded, rotund man in a red Santa suit with an ID reading Kris Kringle falls from the sky in Central Park, Castle and Beckett are on the hunt to find the person who killed Santa. But everything isn't holiday cheer, as they discover St. Nick may have been more naughty than nice. Meanwhile, Castle and Beckett prepare for their first Christmas together
In the aftermath of a disastrous “Meet the Parents” dinner, a bickering Castle and Beckett are sent to retrieve the only witness to a murder. But when they get ambushed, they’re forced to take the witness on the run. Stranded in the middle of the night in a bad part of town, with no phone, badge or gun, Castle and Beckett must find a way to protect him from a team of mobsters who want him silenced -- that is, if they don’t kill each other first.
When the lead guitarist of a rock band is murdered, the documentary crew that were following the band turn their cameras on Castle, Beckett and the team as they try to solve the case. The result is a documentary style episode of “Castle,” which offers us a unique glimpse at our characters as they navigate a world that goes far beyond the rock & roll stage.
When a body is found at a sci-fi convention, Castle and Beckett are warped into the heart of fandom -- a world of egotistic celebrities, diehard costumed fans and enough drama for two galaxies.
While investigating a shocking ritualistic murder, Beckett and her team uncover surprising evidence linking Castle to the killing. As the evidence against him mounts, loyalties are tested, and when surprising revelations come to light, Beckett begins to wonder how well she really knows her new lover and partner of four years.