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 Ryan and Esposito go to where the victim worked, the guy that talks to them was on an episode of the short TV series Moonlight where he played a guy that was stalking a girl after his death. He even tells Ryan that if he changes his mind, he'll give him some hair gel and fangs; the guy was turned into a vampire before his execution.
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.