Mysteries abound when a family returns from vacation to discover a dead man in their daughter’s bed. Thinking they’re investigating the murder of a squatter, Castle and Beckett soon find themselves unraveling a multi-million dollar heist. Meanwhile, Castle tries to keep Beckett from finding out that they’ve been romantically linked when he’s featured as one of New York’s 10 most eligible bachelors.
While investigating the death of an Irish mobster, Beckett and Castle uncover a local turf war that may be connected to both a late-night infomercial guru and an international drug smuggling operation. But the case turns agonizingly personal when evidence emerges that the killer they’re chasing may have had a hand in Beckett’s mother’s murder.
When Castle and Beckett are called to a wedding to investigate the death of a bridesmaid, Castle is stunned to discover that the soon-to-be bride is his old flame, Kyra, “the one that got away” (guest starring Alyssa Milano). Complications ensue as Kyra, caught off-guard by Castle’s reappearance in her life, wonders if she’s marrying the right guy. With the nuptials forestalled and the entire wedding party under suspicion, Beckett questions Castle’s ability to be objective about the case. But when it looks to Beckett like Castle and Kyra might rekindle their romance, her judgment may be compromised as well.
When an art dealer is gunned down in his gallery, Castle & Beckett discover that a bullet is inexplicably missing from the crime scene. The mystery is deepened by an amnesiac who witnessed the crime but can’t remember what he saw or even who he is.
When a murdered man is found stuffed in the garbage chute of an apartment building and two women arrive to ID his body — one his wife and the other his fiance — Castle and Beckett have their hands full keeping the women from killing each other as they work to peel back the layers of the victim’s double life. Was it a jilted woman, corporate espionage, or a much darker secret that led to his demise?
The murder of an Assistant District Attorney thrusts Castle and Beckett into the world of ex-cons and escorts. But when Castle’s desire to help a vulnerable call girl endangers the case, Beckett is forced to decide between honoring promises and putting a killer behind bars. Matters are complicated even further when Castle’s daughter shares a potentially explosive secret with Beckett instead of her father.
Castle and Beckett investigate the hit-and-run death of a bike messenger, brutally murdered to prevent him from delivering a package, the contents of which could free a wrongly convicted man from prison. In a surprising twist, this tragic death is linked to a murder case that Captain Montgomery investigated a decade earlier. To solve the present murder, Castle and Beckett must dredge up the past by uncovering the secrets and scandals of a prominent New York family.
When an up-and-coming rock star’s dead body is found staged in a scene straight out of her hit music video, Castle and Beckett delve into the world of obsessed fans, sleazy managers and jealous band members. But it’s only when Alexis uncovers the true meaning behind the lyrics of the final song that clues to the killer’s identity begin to surface.
As Halloween approaches, Castle and Beckett are called to a graveyard where the body of a young man sporting vampire fangs has been discovered with a wooden stake driven through his heart. Their investigation takes them deep into the heart of New York’s underground vampire fetish community, where they learn that the motive for the victim’s murder may be hiding within the pages of the graphic novel he was writing before his death.
Castle’s book agent, Paula Haas (guest star Debi Mazar), approaches him with a career changing opportunity, but taking it would mean the end of his relationship with Beckett. Will the murder of an unidentified woman found dead in a manhole be their last case together?