Beckett has an interview with a federal law enforcement agency which compels her to reassess her job and her relationship with Castle. The latest case involves skid row and turns up many peculiar things about the death of a young woman found inside a water tank there.
Castle and Beckett find themselves shut out of a crime scene by Homeland Security. Things get complicated when they discover that the victim, a government whistle-blower, was killed by a military drone's missile.
While the team looks for a way to disarm the bomb that Beckett has stepped on, Castle diverts her attention by engaging in an argument about who fell for whom first.
Castle's jealousy surfaces when Beckett is assigned as private protection for charming billionaire Erik Vaughn.
Primate research, big game hunting and Bigfoot all play into the investigation, when Castle and Beckett hunt for a murderer who left giant footprints at the scene.
Castle's stuck in the loft with a broken leg as Beckett investigates an IRS agent's death. Bored and unhappy, Castle spends his time looking out the window where he thinks he's seen a young woman murdered.
Castle and Beckett investigate the discovery of a man found dead in an industrial cake mixer and a link to an Irish Staten Island gang and bar owner, Siobhan O'Doul. Surprising everyone is that Ryan has a history with Siobhan from when he worked undercover in narcotics. With no leads and the case threatening to go cold, Ryan goes back undercover to help find the killer.moreless
A "haunted" video seems to have scared a young woman to death and now Castle is convinced he's next after inadvertently watching the cursed video.
When Castle takes matters into his own hands, after the FBI fail to get Alexis back, he discovers that the kidnapping may be part of something more ominous.
While investigating a murder, Castle and Beckett find a link to a kidnapping plot. FBI Agent Harris is called in to help find the kidnappers.
Castle and Beckett's latest case involves the murder of a rising star. Things don't go as planned when Castle tries to give Beckett a Valentine's Day gift.
Complications ensue when Castle and Beckett finally try to take Senator Bracken down after finding evidence connecting him to a young woman's murder.
When the founder of a hit adult video franchise is murdered, the number of suspects with a motive provides a long list for Castle and Beckett to pursue. Castle isn't happy about the details being made public in Alexis' personal video blog.
Beckett and Castle's investigation into the death of an up and coming DJ forces them to deal with the rough world of the music industry. As the investigation proceeds, Esposito takes a problematic teenager under his wing.
Castle and Beckett find there are plenty of suspects when a powerful divorce attorney is murdered. Chaos, tension, humor and awkwardness abound when circumstances bring Castle's ex-wife, Meredith, and Beckett to both live at the loft.
Beckett and Castle investigate the death of a man dressed as Santa after he drops out of the sky in Central Park. Castle and Beckett get ready to spend their first Christmas together.
Castle and Beckett's unsuccessful meet-the-parents dinner leaves them arguing, even as they must head out to recover a murder witness. A surprise attack leaves them and the witness on the run without a phone or a gun. The two must find a way to keep the witness safe, if they don't kill each other first.moreless
When a rock star is murdered, the documentary crew filming the band continue on by following Beckett and Castle as they investigate.
Drama, celebrities with big egos and diehard fans dressed in costume are all part of Castle and Beckett's investigation when a body is found at a sci-fi convention.
A ritualistic murder puts Castle in the crosshairs as evidence mounts linking him to the killing. Surprises come to light leaving Beckett to question how well she really knows Castle.
Escaping to the Hampton's for a romantic weekend, Castle and Beckett end up in the middle of a murder investigation when a dying man falls into Castle's pool.
A repossessed storage unit, treasure seekers and Manhattan socialites all come together in the case of a woman inexplicably murdered. Castle decides to enter the storage unit auction to see if anything inside might have led to her killing.
It's Beckett's first day back from suspension. When the local TV weather girl is murdered, she and Castle must forge a course through a world of backstabbing and ruthless ambition to solve the case, all while keeping their new relationship a secret.
Picking up the morning after, Castle and Beckett now have to decide if they're a couple or was it just a onetime deal. But before they can tackle that, they must deal with those responsible for Kate's mother's death who are now a threat to Beckett.