In the Season Finale, an interview with a high-profile federal law enforcement agency forces Beckett to reconsider what she wants out of her job — and out of her relationship with Castle. Meanwhile, the body of a young woman is found floating inside the water tank of a skid row flop house, but as the team investigate, they discover that her final resting place is just one of many strange things about her death.
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.
In the first of a two-episode story arc, Castle & Beckett begin a murder investigation that also exposes a plot to kidnap the daughter of a wealthy Middle Eastern businessman. Dylan Walsh ("Nip/Tuck") guest stars as FBI Agent Harris, an even-keeled professional brought in to help find the kidnappers.
After four seasons of "will they" or "won't they," Richard Castle and Kate Beckett finally gave in to their feelings for each other in the much anticipated Season 4 finale. Season 5 picks up on the proverbial morning after, with Castle and Beckett facing new questions -- Was this a one-time fling, or are they now a couple? But before they find the answers, they must take on the forces responsible for Beckett's mother's murder that now threaten Kate Beckett's life.
When a young woman appears to have literally been scared to death three days after watching a "haunted" DVD, Castle and Beckett delve into one of their creepiest cases yet. To make matters worse, Castle becomes convinced that he too is marked for death when he accidentally watches the cursed video. Master of horror Wes Craven makes a special quest appearance.
When Beckett is assigned to protect Erik Vaughn, a charming billionaire entrepreneur whose life is in danger, she's forced to reflect on her relationship with Castle which has begun to plateau. Meanwhile, consumed with jealousy, Castle goes to extraordinary lengths to solve the case and separate the two of them.
Castle and Beckett's plans for a romantic weekend in the Hamptons are interrupted when a dying man stumbles into Castle's backyard, collapsing into his pool. Unable to escape the lure of the investigation they join up with the small town's well-intentioned, but inexperienced sheriff to find the killer.
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 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 Castle and Beckett find giant footprints at the site of a vicious murder, the team is forced to confront the unlikely theory that Bigfoot is the killer. But as they trek into the world of primate research, big game hunting and mythological creatures, they realize that finding the man (or beast) responsible may put them on the endangered species list.