A doctor murdered by a man in a Santa suit pulls Castle into the world of organized crime.
Tropes that appear in this episode:
- A Simple Plan: Lanie told her parents she and Espo are engaged and asks him to play along with it during her parents' short lay-over on their way to Paris. Then their flight gets delayed and they're going out to dinner together. Ryan enjoys the hell out of their predicament.
- Ask a Stupid Question...: The mob's electronics fixer hooked Eric up with hot credit cards.Castle: Stolen credit cards? What would he want those for?
Fixer: Uh, to buy things? Without paying for them? - Blood Oath: Dino forces this on Castle. Castle will find Eric's killer, Dino will let Castle and Beckett bring him to legal justice instead of mob justice.
- Continuity Nod: The victim used the Hytch rideshare app shortly before his death.
- Credits Gag: The opening card replaces the pen with a candy can, has floating snowflakes, and puts the tune in a brassy holiday jingle.
- Earn Your Happy Ending: Ultimately Dino gives his blessing to the relationship between Jane (his daughter) and Luca (the son of a rival family) in hopes of making peace with his rivals.
- Dirty Cop: The killer is an organized crime detective who started shaking down shopkeepers on another mob family's turf. He shot the mobster sent after him and then killed the doctor when he found out the mobster was still alive.
- Fake Relationship: Downplayed. Lanie and Esposito pretend to be engaged so her parents will stop asking about her love life.
- Meet the In-Laws: Lanie's parents are in town on a layover and she wants Esposito to meet them. Unfortunately, they have to pretend to be engaged as Lanie previously told her parents that and they need to maintain the ruse.
- O.O.C. Is Serious Business: Rocco, silent the entire episode, breaks that silence when Castle asks about Luca Tessaro.
- Rape Is a Special Kind of Evil: The mobsters mistook a regular romantic interaction as an assault because Jane made up that last part to keep their secret.Rocco: Luca is a sensitive subject. He is a stain upon this family.
- Star-Crossed Lovers: Jane and Luca are the children of rival families in a secret relationship. The namesake play is even mentioned, although the lovers' story here has a happy ending.
- Sudden Downer Ending: After solving the case, Castle is preparing to enjoy himself at the holiday party. Then Gates informs him that their suspect was killed on the way to jail, and the DA suspects Castle's recent mob ties had something to do with it. As a result, he's no longer allowed to work with the NYPD.
- Wham Line:
- "Luca Tessaro? You're alive?
- At the end, Gates tells Castle that he's no longer permitted to work with the NYPD.
