Someone is not just killing, but doing so ritualistically. Castle's knowledge of obscure rituals points to someone conducting a Vodun findsman's ritual; whatever he or she is doing, it's obvious that something has been lost and they want it back. However, trying to find the truth amid illegal immigrants and confusing facts tests the abilities - and imaginations - of the team.
Meredith: Makes you wonder why we ever got divorced.
Castle: I know, right? I mean, except for you having an affair with your director and moving to Malibu and serving me with divorce papers, I think we really had a chance.
Castle: She's thinking of moving back to New York. Do you know what that would mean to me? That would be a very special brand of hell. The hell of a deep-fried twinkie.
Ryan: A deep-fried twinkie?
Castle: Yeah, the guilty pleasure that you know is bad for you so you only do it once, maybe twice a year for the novelty.
Beckett: Crime scene, dead body. A little respect here.
Castle: I don't think he can hear me.
Beckett: If she's so bad, why did you have sex with her this morning?
Castle: Let me tell you something about crazy people. The sex is unbelievable.
Beckett: How shallow are you?
Meredith: You know, I was his inspiration once.
Beckett: Were you, now.
Meredith: Still am, from time to time. Right kitten?
Castle: I had this dream once. Only I was naked, and far less embarrassed.
Beckett: Castle, are you having a breakdown?
Castle: Not a breakdown, a breakthrough. I really am ruggedly handsome, aren't I?
Beckett: I’m still waiting for the breakthrough.
Beckett: Where did the bag come from? (Castle retrieve the bag from trunk of the car)
Castle: Oh sorry, that’s mine. I felt given everything that’s happened I should be prepared. Got this special order. Look.
Castle: Ah ha, cool huh?
Beckett: No, not cool... you don’t need a vest.
Castle: If you shoot me, do I not bleed?
Beckett: You are not going to get shot and do you know why? Because you are going nowhere near the gunfire. You are staying here.
Castle: Yes, we’ve seen how well that works.
Beckett: Stay here, Castle, and don’t do anything. ('to the cops) All right, this is our guy. Got him? Let's go
(Beckett and Castle are pinned down by gunfire behind a counter)
Castle: I've written this scene about a hundred times. We give him what he wants, you know how it ends? Badly. And by badly, I mean us dead!
Beckett: Just stay down!
Castle: You stay down!
Beckett: I can't shoot him from down here!
Castle: He can't shoot you either!
Beckett: Probably saved my life.
Castle: I definitely saved your life. And you know what that means, don't you? It means you owe me.
Beckett: Owe you what?
Castle: Whatever I want. And, you know exactly what I want, don't you? You know what I really, really want you to do. Never, ever call me kitten.
"Nitro" - Dick Dale
"Make You Crazy (feat. Femi Kuti)" - Brett Dennen
"1, 2, 3, 4" - Plain White T's
This is the episode that Castle purchases a bullet proof vest with the word "WRITER" instead of "POLICE".
Castle, talking about the prospect of his ex-wife Meredith moving back to New York, says that it would be a "very special brand of Hell". This is a possible allusion to Nathan Fillion's previous show, Firefly, where his character, Malcolm Reynolds, is threatened by the Preacher with the "very special level of Hell" if he takes sexual advantage of a (seemingly) innocent young girl. The Preacher's more graphic description is "a level they reserve for child molesters, and people who talk at the theatre."
Meredith, Castle's first wife and mother of Alexis made her first time in the series in this episode and later reappeared in the 5th season's episode "Significant Others". The explanation is also given as to why their marriage failed - Meredith had an affair with one of her directors, then left Castle for the other man and served Castle with divorce papers.
During the gunfight between Kate and the other gunman, at one scene, showing from the other gunman's perspective, Kate lifts her gun to take a wild shot at him. The scene then quickly switches to behind the counter, and again Kate raises her gun to take a pot shot at the gunman.