4.17 – Once Upon a Crime

0
When a woman dressed as Red Riding Hood is found dead in the woods with claw marks covering her body, and soon after a murdered Snow White is discovered with a poison apple in her hand, Castle & Beckett find themselves on a Grimm hunt to catch a fairytale killer before he kills again. But nothing is as it seems in a case filled with deceit, betrayal, secrets and murder.

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.

4.14 – 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.

4.19 – 47 Seconds

0
When a bomb explodes at a protest rally killing five people, Castle & Beckett realize the key to solving the case is to reconstruct the 47 seconds prior to the explosion. Using video and witness accounts, they uncover the shocking truth about who planted the bomb. Christine Woods (“Perfect Couples”) and Tim Guinee (“The Good Wife”) guest star.

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.

4.20 – The Limey

0
A devilishly handsome detective from Scotland Yard, Simon Hunt (Brett Tucker, “Off the Map,” “Spartacus,” guest stars), teams up with Castle & Beckett to find the person responsible for the murder of his friend’s daughter. Also, Charles Shaughnessy (“Days of Our Lives”) plays Nigel Winthrop, the Deputy General at the British Consulate whom Castle & Beckett suspect is up to more than just ambassadorial balls and diplomatic luncheons. Meanwhile, Lanie convinces Beckett that she needs to make a move on Castle before it is too late.

4.21 – Headhunters

0
With tensions rising between Castle and Beckett, Castle finds himself a new partner — Detective Ethan Slaughter (guest star Adam Baldwin, “Firefly”), a tough and colorful cop from the city’s gang unit. But Castle gets more than he bargained for when Slaughter shows him a grittier side of police work that puts Castle in the line of fire like never before.

4.12 – Dial M for Mayor

0
Derek Webster (“Desperate Housewives,” “Damages”) guest stars as Mayor Robert Weldon, Castle’s longtime friend and the Mayor of New York City. It was Mayor Weldon’s political clout that allowed Castle to partner up with Beckett. But now, when a woman is found dead in a car that traces back to the Mayor’s motor pool, that partnership comes under fire as the scandal surrounding the investigation threatens to bring down Weldon’s administration.

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.”

4.13 – 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.