Trivia: Castle's Halloween costume is of Malcolm Reynolds, played by Nathan Fillion in the short-lived TV show "Firefly." Alexis asks him: "Didn't you wear that like five years ago?" Serenity, the film based on Firefly, was released 5 years before this episode aired.
Lucky Stiff - S3-E14
Trivia: Firefly reference. When Beckett is talking to the drug dealer she tells him she likes to feel "shiny". "Shiny" was slang for 'really good' in Firefly.
Close Encounters of the Murderous Kind - S3-E9
Trivia: In this episode, Castle says the words "My partner is crazy and may start firing at any moment" in Chinese. Beckett then asks him "Semester abroad?", to which he replies "Nah, a TV show I used to love". This is a reference to Firefly, a TV show starring Nathan Fillion in which characters occasionally spoke in Chinese.
Trivia: When Castle asks Ryan to say "boyo", it was written that Ryan only said it once. The back and forth volley of "boyos" was ad-libbed by Nathan Fillion and Seamus Dever.
Trivia: In Castle's book 'Frozen Heat', there are a pair of homicide detectives named Malcolm and Reynolds, an in-joke to Nathan Fillion's role in Firefly.
Fool Me Once - S2-E4
Trivia: Firefly reference. In that show, two agents were sent to capture the character River Tam. The agents wore blue surgical gloves and were foreshadowed by River prophetically muttering "two by two, hands of blue." In this Castle episode, after putting on blue gloves ("hands of blue") , Castle holds up two fingers on each hand one after the other ("two by two") then opens his hands.
Trivia: After learning a murdered television host was planning on changing his show-ending signature line, Castle suggests to Beckett that they should have a signature line of their own, and suggests "A whole new chapter in crime solving." This is actually the tag line on the season 1 DVD set. The other line Castle suggests, "She's armed, he's dangerous", became the tag line on the season 2 DVD set.
Trivia: "Fidelis Ad Mortem" is Latin for "faithful unto death", and is the motto of the NYPD.
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.
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.
Trivia: In the elevator, Castle and Beckett have a conversation about his previous relationship with Kyra that mirrors their conversation in "Little Girl Lost", with the roles reversed, about Beckett's relationship with Will Sorenson. (00:20:00)
Smells Like Teen Spirit - S6-E15
Trivia: Near the end of the episode, while dancing at the school dance, Beckett and Castle decide on Andrew Belle's "In My Veins" as 'their song' for the wedding. The same song plays under the end of "Always", the season 4 finale, when Beckett admits to Castle her feelings for him and they consummate their relationship.
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.
Trivia: Throughout the episode, it's heavily implied, short of mentioned outright, that Castle is being considered to write a new James Bond novel. Stana Katic is actually a Bond girl, having had a small role as a Canadian intelligence officer in 'Quantum of Solace'.
Trivia: As a tie-in to the series, shortly after it premiered, ABC began publishing Castle's Nikki Heat books, ghostwritten by a real author and credited to Castle. In 'Heat Rises', a murder victim is mentioned as having owned a copy of the movie 'Air Force One', which was written by "Castle" creator Andrew Marlowe.
Answer: The networks are now having winter breaks. A mid season end of new episodes, when they come back after the new year, it picks up as if several months have gone by. Beckett suggested Valentine's Day as a "chick flick" to watch as she is moved in. Also some episodes are not scheduled to air in order.