An ex-burglar turned soldier is found murdered in an alleyway, having apparently been forced into taking one more job — which transpires to be breaking into Captain Roy Montgomery's former home and stealing his files. Beckett is immediately placed on edge, suspecting that it revolves around her mother's case, suspicions which are confirmed when DNA found on the scene matches DNA found at the scene of her shooting a year before.
Faced with the prospect of locating the man who shot her and finally uncovering the answers she seeks about her mother's death, Beckett begins to spiral back down into obsession again, which prompts a crisis on Castle's part as he must face the decision of informing her of the secret he's been keeping and risk losing her forever, or watch her get destroyed by the conspiracy she chases. His choice will in turn will force Beckett to confront what she truly wants...
- Anguished Declaration of Love: Twice:
- Castle gives another one of these to Beckett as part of a desperate attempt to both (a) justify his keeping secret the contact who was protecting her with Montgomery's files and (b) persuade her to drop the investigation.
- At the end although she doesn't actually say the word Beckett's declaration to Castle before They Do is this trope in practically every other respect.
- Arc Words: "Always".
- Big Damn Heroes: Ryan for Beckett, but she hallucinates that it's Castle coming to save her, which is one of the things that helps prompt an epiphany.
- Bittersweet Ending: Beckett and Esposito are suspended for their actions, prompting Beckett to resign, Esposito and Ryan's friendship is damaged by what Esposito views as Ryan's betrayal, and the man who shot Beckett is still out there and is gunning for her...and her protector. But Beckett has realized that she only wants to be with Castle and goes to him at his apartment, where They Do.
- The Big Damn Kiss: And how.
- Breaking the Fellowship: Played with. The episode ends with Beckett and Esposito suspended, Esposito furious at Ryan for his perceived betrayal and refusing to speak to him, and Castle having washed his hands of Beckett's obsession and breaking with her... which is then subverted when Beckett shows up at his apartment having finally realized that she wants nothing but to be with him, whereupon They Do.
- Call-Back: The Big Damn Kiss mirrors the kiss in "Knockdown", except this time Beckett initiates instead of Castle.
- Epiphany Comeback: Played with — Beckett gets her ass kicked by the man who shot her and experiences an epiphany as she's dangling off the side of a building... except it's not about winning the fight and doesn't help her do so, it's about realizing that she wants a life with Castle instead of throwing it away in pursuit of her mother's killers.
- Holding Hands: Twice. Once early in the episode as a gesture of solidarity and once at the end as they are kissing passionately.
- Mood Whiplash: The ending. Beckett and Castle resolve their UST, but the guy who shot Beckett is still out there, has found Castle's contact, and intends on finishing the job he started once and for all.
- Not So Different: A subtle example; in this episode Beckett, Ryan and Esposito break the rules to bring justice to someone they deem deserving... which is not a million miles away from the actions of the three cops who started the dominoes that ended with Johanna Beckett's murder. Except Ryan has doubts about what they're doing...
- Official Couple: As of this episode, Castle and Beckett.
- Special Edition Title: As with other significant arc episodes in the series, the title card is shaded a different colour from the usual brown (this time green) and features no music.
- They Do
- Turn in Your Badge: Played straight; Gates practically recites this trope word for word to Esposito and Beckett. Taken one step further when Beckett resigns.
- Wham Episode: And how. Seriously.
- You Called Me "X"; It Must Be Serious: Castle towards Beckett, of course, but Ryan and Esposito get in on the act when Ryan confronts Esposito with his misgivings about their entire operation.
- Wham Line: "Beckett, what do you want?" "You." Cue The Big Damn Kiss.
- Also, during the Turn in Your Badge scene:Beckett: Keep it. I resign.
- Also, during the Turn in Your Badge scene: