4.14 – The Blue Butterfly

0
When Castle and Beckett investigate the killing of a treasure hunter, they discover the case is linked to a mysterious homicide from 1947 involving a hard-boiled private detective. Castle realizes the only way to solve the present-day murder is to solve the murder from the past. The 1947 case comes to life through stylized flashbacks, featuring Castle as the private eye and Beckett as a femme fatale.

4.15 – Pandora

0
In the first episode of a two-part “Castle” event, Castle and Beckett pursue a ruthless killer who, they discover, is part of a sinister, international conspiracy. Castle and Beckett are joined on the case by Sophia Conrad (guest star Jennifer Beals, “The Chicago Code,” “Flashdance”), a smart, sexy CIA operative who has a complicated past with Castle. Josh Stamberg, (“Drop Dead Diva”) also guest stars as Martin Danberg, an intelligence officer.

4.03 – Head Case

0
Gunshots, a fleeing van and a massive blood pool all point to murder, but when Castle & Beckett arrive at the crime scene, they discover that it lacks something – the victim! The investigation leads to the cutting-edge world of life-extension science, a cunning high-tech researcher (guest star William Atherton), and a sleazy porn mogul who invested in a modern-day “fountain of youth.” Meanwhile, Alexis finds out whether she got into Stanford.

4.09 – Kill Shot

0
A sniper on a killing spree is terrorizing New York City. With the clock ticking down to the next murder and nothing to go on except a killer with no apparent motive but to instill terror, this could prove the team’s toughest case yet. The hunt is made even more complicated when Beckett begins to experience increasingly strong moments of PTSD – moments she tries hard to hide from Castle and the detectives.

4.08 – Heartbreak Hotel

0
During the investigation of the murder of an Atlantic City casino owner at an abandoned warehouse, strong leads emerge for the team in both New York and Atlantic City. As Beckett and Capt. Gates work the New York leads together, Castle naturally chooses to join the detectives for the road trip to “America’s Playground,” hoping to help solve the case while throwing an impromptu bachelor party for Ryan.

4.16 – Linchpin

0
In the explosive conclusion of a two-part story arc that began last week with “Pandora,” Castle & Beckett race to find the “Linchpin” in order to stop the first domino in a chain of events which will plunge the United States into war.

4.23 – Always

0
When the murder of an Army veteran puts Beckett on the trail of the man who shot her, Castle must decide how much he’s willing to sacrifice to keep her safe. As secrets are revealed and feelings are put on the table, the lives of the detectives at the 12th Precinct may never be the same, on the Season Finale of “Castle.”

4.06 – Demons

0
Castle & Beckett confront the possibility of paranormal foul play when a world renown ghost hunter is mysteriously murdered while investigating a haunting at a legendary New York mansion.

4.04 – Kick the Ballistics

0
While investigating the mysterious shooting death of a young woman, Castle and Beckett face a cop’s worst nightmare when they discover that the gun used in the killing is Det. Ryan’s old service weapon – the one that was stolen by the serial killer, 3XK. Now with the clock ticking, the team must work to solve the murder, track down 3XK and retrieve Ryan’s gun before the killer strikes again.

4.13 – An Embarrassment of Bitches

0
When a famous dog trainer is killed, the investigation keeps coming back to charismatic reality TV star Kay Cappuccio (guest star Hilarie Burton, “White Collar”). Kay, a favorite of tabloids and gossip websites the world over, has achieved stardom without possessing any discernible skill or talent. But there seems to be more to her story than she is letting on.