Beckett's former training officer, Mike Royce, turned disgraced bounty hunter, turned rescuing angel, returns to NYC from LA and gets murdered. Captain Montgomery doesn't give her permission to pursue the case because she's too close to the case. She agrees, so she takes her vacation time. And flies to LA. Castle anticipates this and joins her.
- Abnormal Ammo: The case is focused on acquiring new lightweight bullets that would actually dissolve in the target's body after they were used, making it harder for police to track down the gun used.
- Almighty Janitor: Maurice the concierge is capable to getting Beckett a big whiteboard in a matter of minutes and locating the exact location of the killer at another hotel through his connections among other hotel staff.
- As Himself: Gene Simmons, playing himself, provides Beckett and Castle with some background information on the case upon their arrival in L.A.
- The Atoner: It is suggested that Royce's current reputation as a 'problem-solver' was his way of atoning for his actions during his last appearance.
- B-Movie: Violet's only previous film role was an extra in a zombie cheerleader flick.
- Cigar Chomper: Ganz enjoys fine cigars. This backfires on him when Beckett notices the stub of one of them at the boardwalk and use it to know which direction he went.
- Face Death with Dignity: Royce simply quips to Ganz that he has no idea of the hell he's bringing down rather than fight or beg for his life. Ganz himself is amused and resigned when he thinks Beckett is going to shoot him in cold blood, joking that he never thought hell would look so good.
- The Fixer: Maurice, the concierge at Castle's regular Los Angeles hotel, is so good at getting what Castle needs that Castle speculates he could order the Ark of the Covenant and Maurice would find a way to get it.
- Immediate Self-Contradiction: Beckett's protesting that she is not too emotionally involved in the Royce murder.
- It's Personal: The team knows Royce broke the rules when he went after the treasure last time he showed up, but he was still Beckett's training officer and god damn they're going to find his killers and take them down.
- Jack Bauer Interrogation Technique: Ryan and Esposito have no trouble making one of Ganz' men sweat.Mannis: I’m hit, man. Call an ambulance.
Esposito: Oh, my partner’s on that.
Ryan: 9… 1… what comes after that one? - Laser-Guided Karma: Ganz shoots Royce in the leg, then walks him down, and finishes him off. Beckett then shoots Ganz in the leg and tracks down him, having him at her mercy.
- Missed Him by That Much: Castle and Beckett almost give into their UST but then she leaves the room. He waits for her to come back for a bit, and she does, but at that point, Castle has given up and just left.
- Oh, Crap!: Kelvin when he hears the tape recording of his voice Ganz had Violet make and realizes it could be used to break into his company's vault.
- Redemption Equals Death: "There’s no excuse for what I did, especially what I did to you. But I’m on a righteous path now, and I hope one day that path earns me your forgiveness."
- Serendipitous Survival: Beckett calls the phone of Ganz's accomplice right as he's about to shoot Esposito, Ryan and Violet in an ambush, disorienting him and alerting them to his presence.
- Shout-Out:
- Ganz's alias is that of a character from Heat.
- The episode's title is a pun on that of To Live and Die in L.A..
- Castle offers Det. Seeger a robe from his and Beckett's hotel.
- Show Some Leg: Beckett attempts this by confronting their suspect in a revealing swimsuit.
- Those Two Guys: The actors playing the Ryan and Esposito inspired characters in the Nikki Heat movie.
- Wine Is Classy: Charles Kelvin, the CEO the bullets are stolen from lists wine as a hobby, although he's not too classy given that his other hobby is surfing.
