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.
Paranoia strikes Monroe deeply as Neville disappears and Neville’s son Jason makes a big decision. Meanwhile, the familial bond between Miles and Charlie grows stronger. Elsewhere, Miles experiences romantic attraction with both Rachel and Nora. Rachel sets off on her dangerous quest to infiltrate the Tower and restore power to the world before Monroe can ignite a nuclear device.
Trouble brews among the Night’s Watch at Craster’s. Margaery takes Joffrey out of his comfort zone. Arya meets the leader of the Brotherhood. Varys plots revenge on an old foe. Theon mournfully recalls his missteps. Daenerys deftly orchestrates her exit from Astapor.
As a favor to her mother, Alicia represents software coders in a contract dispute. Peter asks Alicia to renew their wedding vows.
Kiera resurfaces after the mayor is killed in a brazen assassination. She reunites with Carlos to solve the murder and also tries to reconnect with Alec, who has changed since reading the message from his future self.
Rigsby and Van Pelt go undercover as a couple with relationship problems to investigate the death of a woman who received advice from a radio love doctor.
Sarah realizes that the Orphans’ survival is going to take more than police work. But tracking the killer threatens Sarah’s long awaited reunion with her daughter, Kira. As Sarah gets closer to the killer, the killer gets closer to the truth – the ensuing showdown threatens to expose her ruse as a cop.
Annie invites Professor Cornwallis to Jeff’s holiday party in the hope of getting on his good side; when the friends learn Cornwallis intends to give them a bad grade, they decide to take decisive action.
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.
When The Captain asks Lily to move to Rome for a year as his art consultant, she fears that Marshall will resent her. Meanwhile, Ted and Barney become obsessed with a girl who is hiding her amazing body under a puffy coat.