Castle (2009)

The Lives of Others - S5-E19

Trivia: At the act break of the teaser, when the title card is shown and the pen used as the right downward slant in the "A" appears, blood seeps out, forming the number "100." This is the show's 100th episode. (00:10:20)

Still - S5-E22

Trivia: This episode was originally scheduled to air after "The Fast and the Furriest." Because of its subject matter, in light of the bombing at the Boston Marathon, it was postponed for a week and "The Squab and the Quail" was aired in its place.

Probable Cause - S5-E5

Trivia: When Castle is sitting in holding, and Jerry Tyson shows up to taunt him, Tyson's cop disguise has a nameplate with "J. Rook" on it. This is a reference to Jameson Rook, the fictional character in Castle's Nikki Heat books that he based on himself.

The Final Frontier - S5-E6

Trivia: Chris McKenna appears in this episode in a supporting role. As a teenager, McKenna played Joey Buchanan on the soap opera One Life to Live; when he left the show, the character was aged a couple of years and Nathan Fillion was cast as his replacement.

Probable Cause - S5-E5

Trivia: While trying to prove 3XK framed him for murder, Castle identifies "Joseph Vacher", an alias Tyson used, as a serial killer from 19th century France. Active from 1894 to 1897, Vacher murdered and mutilated at least eleven people, and was often compared to Jack the Ripper.

The Final Frontier - S5-E6

Trivia: The voice of Oracle, the computer on the "Nebula 9" ship, is provided by Stana Katic.

Death Gone Crazy - S5-E12

Trivia: When Ryan and Esposito are searching for Jones the bodyguard, the man they first approach is Kris Brkljac, to whom Stana Katic has been married since 2015. (00:05:35)

The Lives of Others - S5-E19

Trivia: Castle, bored at home, begins spying on his neighbors. Writer/creator Andrew Marlowe and writer Terri Miller make cameos (with Castle commenting that they must be writers). (00:06:45)