Soft porn tycoon Beau Randolph was strangled with a bra during a grand party to launch another College Girls Gone Crazy franchise production. He received many death treats, such as from arch-conservative Ronald Armstrong's grim prudish movement. Beau's own bodyguard Scarlet Jones, whom Javier finds irresistible, stole a memory card from his safe and was hired by children's TV production firm. Actress Tiffany Shaw also lies a lot about her disguised party presence, which is only the top of an iceberg of family and business secrets.
A professional hit victim's corpse is found in a parking facility. The team works out she worked for US senator William H. Bracken, whom Becket holds responsible for her mother's murder, but seems to be the actual target. Only Castle learns that Becket hesitated whether to hold back evidence before another clue lead the team to prime suspect Robert McManus, a fired mechanic who blames the senator for his son's suicide. The senator is hell-bent on holding a high-profile speech in a hotel to launch a career-crucial environmental bill.
The corpse of Hannah Green, star of a fashion house reality show, is found in a Manhattan alley, but she has bruises from captivity elsewhere for the day she went missing from the studio. The team unravels complex rivalries for parts, infidelity and spin-offs, both a clothes line and Margo's son Stone Gower's series project with co-star Collette's daughter Ashley. Castle and Becket fear the captain will discover their affair after he accidentally drops her Valentine's present in the captain's coat
Saudi student Hasim Farouk, at Columbia like Alexis, is killed by a van crashing into him while he fired at it. The team soon works out the van was used to kidnap not only Egyptian tycoon Anwar El-Masri's daughter Sara, but also Alexis, whom she met at a lecture. FBI agent Harris's sole trace, obtained only because Becket 'turned away' from Castle slightly torturing the wounded van driver, runs dead. Meanwhile the girls attempt an escape, but discover the container they were held in now stands in Paris.
Castle is shaky after watching a DVD which predicts, in flashy amateur horror style, the exact time of death, for no apparent reason and probably by panic-caused cardiac arrest, of the murder victim, screaming in the phone, who received it. Her ex has a solid alibi and couldn't make sense of her panic about 'it'. Tracing the DVD's shipping leads to another copy recipient, killed at home similarly. Their only link is having been jurors on executed country serial killer Nigel Malloy's trial. The team heads for his home town, loved-ones and surviving jurors.
The corpse of Jimmy, a baker popular for cup cakes, is found in his industrial dough mixer. His apprentice Todd noticed, before being sent away, someone arrived in a rare collectors car, probably belonging to Irish mob lord Robert 'Bobby S.' Shannon's right hand, Liam Finch. After FBI agent Sam Walker tells Jimmy was his informant, Ryan astounds his team by revealing he has been undercover in that gang years ago and chooses to revive his alias Kevin.
Castle is home, mostly alone, in a wheelchair after a skiing accident, bored out of his wits just before his birthday. After a while, he actually picks up a pair of binoculars Alexis gave him to play Rear Window. Indeed, right across the street a foxy resident betrays her studly husband with a younger hottie. Shortly after, the cheated husband finds his rival's hat, wields a knife and seems to dispose of the corpse while she isn't seen again. Yet his NYPD team mates only reluctantly investigate and can't find any proof. Castle becomes obsessed with the possibility ...
Castle is jealous when Beckett has to protect a billionaire from an unknown killer. Castle wants to solve the case fast because it means Beckett will no longer have to be with the charming entrepreneur.
After tracking a killer to his apartment, Beckett steps on a bomb trigger and must stand in place while the bomb squad finds a way to defuse it. Castle stays with her, and they argue over who liked who first, via flashbacks.
When Homeland Security inexplicably seals the crime scene of a car bombing, Castle and Beckett find themselves with two mysteries on their hands: who murdered the victim, a government whistleblower, and why are federal agents trying to take over the case? The plot thickens when they discover that the victim wasn't killed by a car bomb but by a missile from a military drone.
The team investigates the death of a woman who hacked a law office for a specific file. It seems she thought her best friend was killed, and she was on a lead to that killer. Beckett interviews with the FBI.
Castle and Beckett are engaged. Beckett starts FBI training in Washington D.C. and is assigned to a case. Someone broke into a secured building and may have stolen codes. Castle flies to D.C. and is exposed to a deadly toxin. The code theft was a diversion.
A woman wakes to find her boyfriend murdered in her apartment. She eludes police and takes hostages and waits for Castle to help her. Castle believes she has been framed, and works with the team to prove her innocence.
A grisly murder investigation leads Castle and Beckett to a suspect who claims he's traveled back in time to stop terrible events from unfolding, events that will change the course of human history. Is he simply a deluded killer, or is it possible that he's telling the truth.
The team investigates the ritual murder of a woman. Symbols on the woman's body and the items left in her apartment seem reminiscent of The Da Vinci Code. Alexis and Pi have moved to their own apartment. Castle finds it hard to accept.
Alexis volunteers in a criminal review organization to help prove a man was wrongly accused of murder 15 years ago. With his execution scheduled in three days, Alexis asks her father to bring a new look at the evidence.
A man dies inside a church, protecting a baby. The team has to find the guy's killer and the baby's parents. The man is connected to a crime, but he protecting the baby does not fit a criminal character.