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* QuipToBlack: Castle, on a regular basis. Nobody else is amused. Beckett also gets to play sometimes. Played with in "Swan Song" where both Esposito and Castle attempt to set up these situations for the camera crew following them. Castle even provides sound effect and musical cues. [[spoiler: Esposito probably would have too but that would have ruined the surprise in the denouement where Esposito sings for real.]]
* {{Qurac}}: Played with in the second season finale. Beckett swallows the existence of a threat to the Banking Minister of the Republic of Luvania even though she had never heard of the country before, until Castle points out that it doesn't exist.
* RabidCop: Beckett in "Kill Shot" when interrogating a suspected sniper. Understandable since this happened right after [[spoiler:she was shot]].
** Beckett also turns nasty in "Always", emphatically provoking the wife of a murdered gang member in trying to go after the sniper who shot her.
** In "Murder, He Wrote", Ryan with a suspect when he [[spoiler:understands that Beckett and Castle are dating]].
** Played with in "Reality Star Struck", where Castle and Gates get Beckett to act this way while interrogating the husband of a reality TV star.
** Played straight in "Hunt" where Beckett kicks the seat from under a very uncooperative woman she's interrogating and lashes out to get her to talk.
--> '''Beckett:''' Now, you don't talk to cops? Well, I'm not a cop today, honey.
* RaceAgainstTheClock: As the title indicates this happens in "Countdown". [[spoiler: Partially subverted since the clock actually reaches 0, but Castle still manages to prevent the bomb from blowing up]].
* RealityEnsues: In "Always", [[spoiler:Beckett faces the man who shot her in hand-to hand]]. Despite her best efforts, she can't put a scratch on him, and he just beats the crap out of her without remorse. Because this isn't the kind of show where a woman who is still recovering from injury [[note]]Note how few fights she gets in during season 4[[/note]] can beat an experienced martial artist and hitman who does this sort of thing for a living. Ryan even warns her the guy might be too much to handle, and she still pursues him even after he stuns her and knocks out Esposito, who is former Special Forces and an even better fighter than she is.
* RealitySubtext: Andrew Marlowe has suggested that the dynamic between Castle and Beckett -- specifically, a writer and his 'muse' going on to develop a romantic bond with each other -- mirrors his relationship with fellow writer Terri Miller.
* RealLifeRelative: Seamus Dever (Ryan)'s wife Juliana has a recurring role as Jenny, Ryan's girlfriend [[spoiler:and later, fiancée, and much later, wife]].
** The cast and crew have utilized it to very cute and very meta ends--such as creating a wedding website for Jenny and Ryan with the Devers' pictures.
* RealLifeWritesThePlot: In Seamus Dever's Episode Commentary for "Wrapped Up In Death", he says he broke his ankle three weeks before taping, encouraging the viewer to see how well he hides his limp. In the climax, the perp runs right past Ryan and Esposito, but instead of chasing after him, they just wave at him (the better to hide Dever's injury).
* ReallyGetsAround: In the pilot, when Castle's mother says that he "never had a father figure" as an excuse for his misbehavior, his reply is that he had dozens of them. Castle himself has a lot of female groupies. Lampshaded by Esposito in "Suicide Squeeze" when he jokingly comments on how active Martha probably was during the 1970's. Probably a mistake to say this directly to Castle, however, who is less than amused.
* RearWindowWitness: In "The Lives of Others", Castle is so bored while recovering from a snowboarding accident, he starts watching his neighbors with binoculars, and sees what he's convinced is a man murdering his girlfriend with a knife, but neither he nor Beckett can find any hard evidence, so everyone except Castle is convinced he's just going crazy with boredom. Beckett even refers to it specifically as a "rear window scenario". [[spoiler:Turns out Beckett staged the whole thing as a birthday present to Castle, and everyone, including the "murderer" and "victim", were in on the prank.]]
* {{Recycled IN SPACE}}: [[Series/MurderSheWrote Jessica Fletcher]] [[foldercontrol]]

[[folder: as a hot middle-aged guy! ]]
Alternatively, ''Series/MurderSheWrote'' [[XMeetsY meets]] ''{{Moonlighting}}'' and/or ''Series/RemingtonSteele''. Except that, unlike in ''Series/MurderSheWrote'', [[WMG/MurderSheWrote Castle isn't the killer]]. Or ''Film/TheThinMan'', only they're not married ([[UnresolvedSexualTension yet]]) and she's the detective.
** Given a full episode lampshade in "Murder, He Wrote".
* RedHerring: {{Lampshaded}}.
** One of the biggest happens in "Pandora"[=/=]"Linchpin". [[spoiler:It happens twice: the two times they think they have found TheMole, it turns out that they are [[RedHerring Red Herrings]] laid out by the real mole, Sophia Turner.]]
** In the two-parter "Target" and "Hunt": In "Target" the daughter of an Egyptian partisan is kidnapped and [[spoiler:Alexis is also a victim of the kidnapping.]] In the second part "Hunt" it is revealed [[spoiler:that Alexis was the real target and the other girl was a target of opportunity to raise the profile of the case. It was a trap for Castle's father, a CIA operative, all along.]]
* RedemptionEqualsDeath: As revealed in the season 3 finale, [[spoiler:Montgomery was the officer with [=McCallister=] and Raglan at the initial incident that led to Beckett's mother's murder. He dies killing Lockwood and his cronies.]]
* RedemptionInTheRain: Part of Beckett's epiphany in "Always" involves her brooding in the rain while sitting on a swingset. WordOfGod confirms that it's the same swingset she and Castle earlier had a meaningful discussion at in "Rise".
* RelationshipUpgrade: [[spoiler: As of the season 4 finale "Always", Castle and Beckett.]]
* RemonstratingWithAGun: Castle in the season 3 premiere.
* {{Retirony}}: At the end of "Pretty Dead", [[spoiler:Captain Montgomery's anniversary gift to his wife is his intention to retire from the force. Although it's waved off as typical Montgomery talk ("He retires every six months", Beckett says), he's dead by the end of the next episode, "Knockout".]]
* TheReveal: Castle's birth name is finally dropped in "He's Dead, She's Dead". It's [[spoiler: Richard Alexander Rodgers]], which is incredibly amusing considering the daughter of a murdered psychic told Beckett that a man named [[spoiler: Alexander]] [[{{Foreshadowing}} would be very important to her...]]
** In "Hunt" [[spoiler:we meet Castle's father and discover he is a CIA operative, which is why he was [[DisappearedDad never around]].]]
* RevealingCoverup: The most common way Castle and Beckett figure out whodunit.
* RippedFromTheHeadlines: A frequent trope for this show, though happily not usually very anvilicious.
** The plot of "The Late Shaft" has a lot of similarities to the Jay Leno[=/=]ConanOBrien ''TheTonightShow'' controversy, as well as elements of DavidLetterman's affair scandal.
** More disturbingly, the two-parter "Setup" / "Countdown", where homeland security current events like high-pressure interrogations, weapons of mass destruction, and racial profiling make their appearance.
** Then, in "47 Seconds", an Occupy Wall Street clone stages a bombing, just in time for a failed attempted bombing by the OWS leaders in Cleveland.
* RomanticFalseLead:
** Two of them in "The Third Man", each a date brought by Castle and Beckett to the same restaurant unawares. It lasts for all of 30 seconds before they're both making excuses to conspire about the case. Also a case of PairTheSpares because Beckett's date starts talking to Castle's date as Beckett and Castle leave the restaurant.
** Detective Tom Demming appears to be shaping up to be one of these for Castle, regarding their mutual interest in Beckett. [[spoiler: He certainly provided a rude awakening for the GenreSavvy shippers who noted his tendencies and [[DieForOurShip pegged him as the killer]] because he was the first one not of the main cast to talk to one of the main cast, and because he had connections to the victim. He wasn't.]]
** As of "Overkill", [[spoiler: he is definitely the RomanticFalseLead. Everyone fire up your computers; it's time for DieForOurShip]]. Alexis even does some LeaningOnTheFourthWall at the beginning of the episode, when Castle asks her to criticize a portion of his next Nikki Heat book, which, in case you've forgotten, is loosely based on what he does with Beckett.
--->'''Alexis:''' [[LampshadeHanging Who's this new guy? It seems like he came out of nowhere.]]\\
'''Castle:''' He ''did'', didn't he?
** In the third season, Gina and Josh take these roles for Castle and Beckett respectively, but were mostly TheFaceless throughout the first half of the series. [[spoiler: After "Poof! You're Dead", Gina is out of the picture. And by the first half of "Rise" (the fourth season opener), Josh is too.]])
** In "The Limey", Castle hooks up with a flight attendant some time after hearing [[spoiler:Kate say that she remembers everything that happened after she was shot]]. Colin, the British policeman, becomes this for Kate.
* RoomFullOfCrazy:
** There's one in the pilot, full of pages from Castle's books, and child-like crayon illustrations of the murders from the novels.
** Scott Dunn from the season 2 two-parter "Tick, Tick, Tick..."/"Boom!" also has one, filled with pages from ''Heat Wave'', detailing his obsession with the character and its inspiration.
** "Linchpin" features a room full of strings and newspaper clippings, some of which depict hypothetical future headlines. The many disparate strings are tied together by a picture hung on the ceiling: that of a Chinese girl, [[spoiler:the eponymous linchpin whom a mathematician theorizes that, if she is murdered by rogue CIA agents, would instigate a world war resulting in millions of American casualties]].
** Lampshaded by Castle, when he sees that Beckett keeps a wall full of crazy with the details of her mom's murder. She'd never shown it to anyone, even her boyfriend.
* RuleOfCool: In "The Final Frontier," the murder weapon is a real-life RayGun.
* RuleOfFunny: In "Heartbreak Hotel," Castle, Esposito, and Ryan get thrown out of an Atlantic City hotel because they're out of their jurisdiction. Do they call the Atlantic City PD for help? No, they sneak in by ''dressing up in Elvis costumes''. And it's hilarious.
* RunningGag:
** Very frequently will someone catch Beckett and Castle in a highly {{UST}}-charged relationship moment or situation and[=/=]or will allude to them being [[SheIsNotMyGirlfriend in a relationship]], prompting Beckett and Castle to respond simultaneously -- with completely different responses (usually with Beckett hotly denying it and Castle cheerfully confirming it). Often something along these lines:
-->'''Ryan''': Are we interrupting something?\\
'''Beckett''': [[SheIsNotMyGirlfriend No!]]\\
'''Castle''': ''[At the same time]'' [[GenreSavvy Yes!]]\\
''[Beckett {{Death Glare}}s Castle]''\\
'''Ryan''': ... Okay.
** A variation pops up in season five [[spoiler: after Castle and Beckett's RelationshipUpgrade]]; Castle and Beckett will either be flirting when the name of Person X (usually Ryan or Esposito, although Alexis has had at least one turn as well) happens to come up or vehemently insisting how it is vital that Person X doesn't find out their secret when, almost like magic, Person X will pop up behind them and say:
-->'''Ryan[=/=]Esposito:''' What [about/shouldn't you tell] me?\\
'''Castle''' and '''Beckett:''' ''{[[BadLiar A bit too quickly]])'' Nothing[=/=]Don't worry about it.
** In the first couple of seasons, whenever Castle mentioned who he was and his previous character, Derrick Storm (who was killed off in his most recent book before meeting Beckett), the person he's talking to would immediately enthuse "Derrick Storm? I love that guy! Why'd you kill him?"
** Castle's GrammarNazi tendencies and minor BerserkButton over people misusing {{Irony}}.
** Castle and Beckett completing each other's sentences, usually leading to a breakthrough in the case.
** Castle's more offbeat theories about the case of the week will almost inevitably involve the CIA at some point.
** Castle has a tendency to get [[ManlyTears weepily emotional]] at significant or sentimental moments, particularly those involving the realisation that his daughter is growing up. He ''also'' has a tendency, when pressed on whether he's crying, to come up with some lame excuse to cover them ("No, it's the onions!").
** Ever since 'Lucky Stiff', whenever Castle has a favor he needs from Ryan and / or Esposito their response will usually be to demand to borrow his Ferrari in return. Each time, the lengths of time they want it for get longer.
* TheSadisticChoice: In "Knockout", [[spoiler:Lockwood comes to Captain Montgomery and demands that he lure Beckett into a trap so they can kill her or else he'll kill Montgomery's family. Being a noble and great man, he TakesAThirdOption, sacrificing himself to kill Lockwood and his crew.]]
* SafeWord: Castle's is "apples", as he repeatedly mentions to Beckett.
* SaltAndPepper: Ryan and Esposito. Beckett and Lanie.
* SamusIsAGirl: In "Heroes and Villains", [[spoiler: the (original) Lone Vengeance]].
* SayingTooMuch: In the pilot, the brother of one of the victims, when questioned for an alibi, helpfully provides alibis for all three of the murders. While Castle is downhearted, Beckett immediately pegs that while it's plausible he'd know his alibi for his sister's murder, the fact that he was instantly prepared for one for ''all three murders'' is more than a wee bit suspicious. [[spoiler: Yep, he did it.]]
* ScaryBlackMan: In "Law and Murder", the accused in a high-profile trial, as well as his friend. It later turns out both are innocent of the murder of one of the jurors.
** This happens again when Beckett is investigating her mom's murder. She immediately keys in on Vulcan Simmons, who is happy to taunt and provoke her. She snaps and assaults him, which with no evidence against him gives him the leverage he needs to walk. Which of course was his intent.
* ScaryMinoritySuspect: Several. Usually WronglyAccused.
* ScreamsLikeALittleGirl:
** In "The Third Man", [[spoiler: Castle does one when he opens a refrigerator and an unexpected body falls out. Surprisingly, no one calls him out on it.]] Presumably a second occurrence happens just off-screen in that episode, as Castle was menaced by a big hairy spider.
** Also he does a small one in "Tick, Tick, Tick...", when [[spoiler: Beckett opens the door for him with a gun in her hand, thinking it's the killer. ]]
** Parodied in the [[HilariousOuttakes outtakes]] when Stana opens the file of a plastic-surgery patient and Nathan glances over at the picture before letting out a high-pitched, girly scream that startles the woman standing next to him and causes the rest of the set to crack up.
** Invoked in "Cuffed" when Castle and Beckett are hanging from a pipe [[ItMakesSenseInContext with the tiger]] below them. The plan to escape becomes "scream like little girls"--which, incidentally, is what catches the attention of Ryan and Esposito, who just happen to be nearby.
* ScrewTheRulesIHaveConnections:
** A non-villainous example would be Castle himself, who has the mayor on speed dial and can thus convince the NYPD to let him shadow Kate around indefinitely.
*** Captain Montgomery ultimately subverts this in the season 3 finale. He later reveals to Beckett that he could have gotten rid of Castle at any time ("The mayor doesn't run this place, I do"), but only kept him around because he thought it would be good for her.
*** Also subverted by the fact that the mayor is not merely doing Castle a favor, but is using his fame as a bestselling author to improve the police's reputation... as well as his [[SlaveToPR chances to get reelected]].
** Castle does the same thing in the pilot when he learns that the fingerprints normally take a week to process and also later, in "Fool Me Once", to learn if a dead body is a CIA agent.
** By the second season, the NYPD has basically said "screw the rules, you're actually incredibly helpful," and after resolving that rather uncomfortable tension with Beckett in "Deep In Death," the two are getting along fine, though they still exchange plenty of wit and snark. So now Castle just keeps helping with the cases, ostensibly still under the guise of novel research, but more because both he and the NYPD like having him around. As of the end of the season 2 episode "When the Bough Breaks", he's on contract to write three more Nikki Heat books, meaning he's still fulfilling his original purpose.
** In "The Third Man", Beckett does this to get into a high-end New York restaurant, surprising Castle, who didn't expect she had those kinds of connections. (He, of course, has plenty.)
** In "Den of Thieves", Montgomery pulls a few strings to expedite a police report that could reveal a mole in a mob investigation from another precinct (which Esposito used to cover.)
** Also, in "Kill the Messenger", Montgomery pulls more strings to smoke out a corrupted prison guard. Later subverted when a rich suspect threatens to call the police commissioner, Montgomery replies "Tell him I said hi. [[RefugeinAudacity And that I could use a raise.]]"
** In "Setup", Castle offhandedly mentions that he's friends with the state governor in order to prevent Agent Fallon from kicking him off the case. [[spoiler: Later subverted; when Fallon eventually ''does'' kick Castle (and Beckett) off the case he comments that he's asked the governor about Castle -- and the governor's never even heard of him.]]
** In "Rise", Castle uses this again on Captain Gates, Montgomery's successor. Raising the question of whether Montgomery could indeed have gotten rid of Castle if he wanted to or not.
*** Though it could also be Gates would rather keep her position by kowtowing to the mayor than lose it by doing something technically within her power, but...
** More villainous when done by Senator Bracken, the BigBad. He continually does this to thwart attempts to investigate him.
** Castle tries, and fails, to do this to save himself from 3XK. Despite the support of the department, and even Captain Gates, the DA refuses to even keep him in holding-- she insists that he be transferred to prison.
*** So, pulling strings of a different sort, Castle stages an escape.
*** Then gets the charges dropped on the escape.
* ScullyBox: Beckett's impractical-for-police-work high heels are this for Stana Katic.
* SecondLove: Beckett for Castle. His first real love was Kyra Blaine, introduced in "A Rose For Everafter." It's entirely possible there's some more out there, as we don't know who else he dedicated his books to (not to mention his two ex-wives).
** He gets another before-Beckett love in Sophia Turner in "Pandora" and "Linchpin". Too bad she's never really left her FirstLove: [[spoiler:The USSR.]]
** In "The Wild Rover" it's confirmed Jenny is Kevin Ryan's second love...though his first love was obtained while he was under an assumed identity while he was infiltrating an Irish gang.
* SecretKeeper: In "Cops and Robbers", a priest plays SecretKeeper to the exact location of an abused wife who faked her and her son's death to hide from the powerful, and connected husband. Thankfully, the priest was more than willing to tell Kate and Castle the location of the two when he learns the abusive father has learned of them.
** As of "Murder, He Wrote", Ryan now knows what's really going on between Beckett and Castle, but chooses not to tell Esposito about it, despite the latter being desperately curious about Beckett's new boyfriend.
** In "After the Storm" Captain Gates invokes this when she tells Beckett [[spoiler:she knows Beckett is keeping some secret about the dead Captain Montgomery]] and guesses it could smear the name of an otherwise good man. She informs Beckett she won't press the matter as she doesn't want to do that anymore than Beckett does.
** In "Probable Cause", Ryan decides to tell Esposito [[spoiler: to emphasize how high the stakes really are with Castle being arrested for murder. Beckett also heads straight to Lanie after Castle's arrest]].
* SecretSecretKeeper: It's revealed in "Still" that of ''course'' [[spoiler:Captain Gates knows about Beckett and Castle]]. What is she, blind?
* SelfInsertFic: What Castle essentially turns his narration of the Blue Butterfly case into, as he visualises what the detective wrote, but overwrote relevant persons with himself and his friends. He even tries to get Ryan to say "Boyo" a few times (Ryan plays the role of an Irish thug in the narration), and flubs his narration and accidentally says Kate's name in place of Vera's (the detective's LoveInterest).
** The Nikki Heat series of novels is basically this.
** And, we later realize, the Derrick Storm novels as well.
* SendingStuffToSaveTheShow: "One Life to Lose" has an in-universe inversion; a group of fans arrange to mail in axes as part of a campaign to get a soap opera's head writer fired.
* SerialKillingsSpecificTarget: In the pilot, the killer [[spoiler: murders his sister for her money, then stages the murder to look like something out of one of Castle's books and commits two similar murders so it'll look like one of her clients — who's obsessed with the books — did it]].
** The plot is revisited when a crazy obsessive is arrested for plotting Senator Bracken's assassination. Castle uncharacteristically tells Beckett that it's open-and-shut and to let it go. Considering that Castle never thinks this way, the allusion is likely intentional and an indication that Castle was actually trying to let Bracken die-- something he later admits to Bracken he would have done if he'd had the chance.
** This trope is also followed in "Scared to Death".
* SeriousBusiness: In "A Deadly Affair" the entire precinct seems pissed off that Castle didn't call them at all during the summer off -- Esposito said he should've [[spoiler: let Ryan shoot him when they caught Castle in a murder victim's apartment or at least locked him up out of spite because of it. Montgomery offers to do just that.]]
** It's less that he didn't call them and more that he didn't call Beckett, who was hurt by it and had just dumped her boyfriend to be with him (unbeknownst to Castle, though, who had finally given up).
* SexWithTheEx: In "Always Buy Retail", Castle sleeps with his first ex-wife when she rolls into town for a short time. He compares it to the guilty pleasure of a "deep fried Twinkie". More seriously he re-kindles a romance with his second ex-wife in the season 2 finale when he thinks Beckett is serious with Demming.
* SharedUniverse: [[http://castletv.net/richard-castle-cameo-in-missing/12782 Richard Castle]] apparently exists in the universe for ''[[{{Missing2012}} Missing]]'', another ABC show.
** Which is made odd by the episode "Hunt." When [[spoiler:Alexis]] is kidnapped Esposito makes references to the movie ''{{Film/Taken}}'' as well as the show ''Missing''.
** The show also mentions [[http://en.wikipedia.org/wiki/Hudson_University Hudson University]], which links it to several shows from different networks.
** The show takes place at New York City's [[BarneyMiller twelfth precinct]].

* SharpDressedMan: Castle has some ''really'' nice suits. Ryan also has a penchant for wearing three-piece suits to work.
* SheCleansUpNicely: Beckett in several episodes ("Home Is Where The Heart Stops", "When The Bough Breaks", "The Third Man", "The Final Nail", "The Limey"). Said literally to her, too.
** This trope also applies to Lanie in "The Double-Down", "Reality Star Struck", "The Blue Butterfly" and many other episodes. "Quit looking at the girls, Castle!"
* [[HesBack She Is Back]]: in "Rise", after having suffered a HeroicBSOD when [[spoiler:a suspect pointed a gun at her]], Beckett has to face the actual killer, who [[spoiler:is pointing a shotgun at her]]. She seems to be on the throes of a BSOD again, but Castle talks her down and she manages to pull through.
* SheIsNotMyGirlfriend:
** Brought to a head in "The Third Man" thanks to a newspaper article saying they're romantically involved.
** "Kill the Messenger." Goes approximately like this:
--->'''Beckett''': No.\\
'''Castle''': ''[Simultaneously]'' Not yet.\\
'''Beckett''': *[[DeathGlare glare]]*
** Comes up again in "Cops and Robbers," this time said word for word.
** Later, in "Cloudy, With a Chance for Murder", they're denying a relationship that has finally been kindled, to avoid NYPD rules.
* SherlockScan: Castle pulls this on Beckett in the pilot, as a sort of attempted LetsGetDangerous moment to prove that he can actually help. It's played with in that Castle realizes as he's doing it that he's hurting Beckett and digging up painful memories for her, and apologetically stops without taking any satisfaction in being correct.
* {{Shipping}}: Beckett gives a dictionary definition InUniverse of this in "One Life to Lose" along with the PortmanteauCoupleName of "Fox Can." The first suspect was also suffering a bad case of DieForOurShip for "Can Fonso."
** In the same episode, Castle works out the PortmanteauCoupleName for Esposito and Lanie, "Esplanie". "Which is perfect, because they're always esplaining things!" Shippers for these two have used the term ever since.
** They later use the Official Fandom term Caskett in the series to refer to themselves.
** Perlmutter/Lanie shippers, sadly, have yet to hear "Perlanie" used on screen, despite the fact that the two actually get along when they're both on together. *cry*
* ShipTease: The entire point of the scene where [[ItWasHisSled Castle and Beckett kiss]] in "Knockdown". Well, that and [[spoiler:to have a guard let down his guard long enough for Beckett to pwn him.]]
** Find an episode that doesn't tease Castle and Beckett. Go ahead. We'll wait.
** The episode "Cuffed" is one big ShipTease, from the first scene where Castle and Beckett wake up with their left hands cuffed together, to the last scene, where Beckett hints at wanting to be cuffed to Castle again.
** Possibly the most blatant ShipTease so far was Ryan's wedding in "Till Death Do Us Part", where the show closes with Castle and Beckett walking down the aisle, hand in hand.
** "An Embarrassment Of Bitches" unexpectedly teases Esposito and Kay Cappuccio, but that never goes anywhere.
** "The Blue Butterfly" requires clearance from the US Dept of Customs to watch, there's so much shipping going on there.
* ShipperOnDeck: Lanie is the most obvious, but close behind her are Ryan, Esposito, Alexis, Martha, Montgomery... hell, it'd be easier to list who ''doesn't'' ship Castle and Beckett during the course of the show. Such as Gates. Notably, however, [[NewOldFlame Kyra Blaine]], Castle's first love, is ''also'' this. She pretty much explicitly gives Beckett her permission-slash-blessing!
** And then, when beta (or gamma) offscreen couple [[spoiler:Esplanie]] is revealed, everyone else is fully in favor.
** There are even hints that Gates, despite hating Castle and officially not knowing about the romance between the two, might be quietly looking the other way. [[spoiler:This is explicitly confirmed in "Still", when Gates rather exasperatedly tells the just-saved-from-a-bomb Beckett to go ahead and kiss Castle, already.]]
* ShoutOut: Has its own sub-page. See ShoutOut.{{Castle}}.
* ShowWithinAShow:
** "The Late Shaft" - Bobby Mann Live is a mashup of the Letterman/Leno/O'Brien/Fallon late night TV shows, where the host Bobby Mann (played by Tom Bergeron) is the Victim of the Week
** "One Life to Lose" - Temptation Lane is a shoutout to daytime soaps.
** "Nebula 9" - A ShoutOut to ''{{Series/Firefly}}'' (due to its short life and cult following) as well as ''Franchise/StarTrek'' and ''Series/BattlestarGalacticaClassic''.
* ShowerScene: Beckett gets one in "Tick, Tick, Tick". The scene has many variants of the trope; the shower silhouette, the in-shower cam, the leg washing, the stepping into a towel, etc. [[IncrediblyLamePun It gets hot.]]
** She gets nekkid again for a glass of wine and a long, hot bath with a Rick Castle book.
* ShownTheirWork:
** Castle researches the material in his books before he writes them so as to present an accurate depiction of the subject matter. However that doesn't stop him from taking ArtisticLicense with [[HollywoodVoodoo certain subjects]].
** In "Always Buy Retail", Castle brings in an expert on Voodoo he'd used in his books. She explains that voodoo is a serious religion, and that Castle had sensationalized it with gratuitous sex imagery.
** In one episode, a killer was said to have been synthesizing [[http://en.wikipedia.org/wiki/RDX cyclonite (a.k.a. RDX)]] from formaldehyde. While formaldehyde is not a directly used in the synthesis, it is used to manufacture of the reagents used in synthesis. A sort of pre-precursor if you will. It was pleasantly surprising that the writers bothered to give a plausible method.
** In "Wrapped Up In Death", the producers used a bio lab tech to show that they know what Carbon-14 dating is ([[Series/{{CSI}} unlike some other shows]]), and why it would work on mummies...and why it wouldn't work with the mummy in question. [[spoiler:It's only a 4-month-old mummy.]]
** In "The Late Shaft," Lanie gets a chance to explain MAO Inhibitors, and that you shouldn't take anything fermented with it (especially not balsamic vinegar).
** In the season 2 finale, a bullet fragment is said to have been fired through a polygonal rifled barrel, such as those found in Glocks. Not only would it actually be possible to discern that from a bullet fragment, Glocks actually are one of the most common handguns to use polygonal rifling.
** In "Punked" the writers managed to accurately portray SteamPunk, actually contracting many professional Steampunk costumers for the club scene and having Castle deliver a very accurate summation of the philosophy of the subculture. This was especially rewarding after the poorly researched equivalent in ''Series/NCISLosAngeles''.
** "Last Call" gives us a pretty detailed history of New York during Prohibition, where there were a lot of speakeasies, supposedly because Mayor Jimmy Walker was an opponent of Prohibition.
** Sadly, ''not'' used in "Undead Again", where the drug scopolamine's effects are totally mis-stated.
* SingleTear: [[TheCutie Ryan]] is the only one crying when they meet in "Knockout", [[spoiler: after Captain Montgomery's death.]] A perfect single tear rolls down his face.
* SleepCute:
** The episode "Close Encounters of the Murderous Kind" has Rick Castle and Detective Beckett wake up in her police car after they were taken, interrogated then drugged by mysterious government agents. Later they are asked "Are those hickeys?" "I wish... They're from the injectors" he answers.
** At the very beginning of "Cuffed", before they realize that they were--yet again--kidnapped and drugged.
* SlidingScaleOfIdealismVersusCynicism: Castle's generally a lighthearted optimist who's more willing to see the best in people, where Beckett's more of a hardened cynic who's more inclined to think the worst. Both have had their belief systems challenged, but the series seems to be leading to Beckett gradually warming to Castle's viewpoint of the world more than vice-versa.
* SlutShaming: A rare male example. Beckett is happy to shame the show's resident slut, Castle, who shrugs it off with good grace. See also: UrbanLegendLoveLife.
* SmugSnake:
** The killer, [[spoiler: Scott Dunn]], in "Tick... Tick... Tick...[=/=]Boom!" -- he clearly ''wants'' to be a MagnificentBastard and spends most of the two-part episode one step ahead of the police and the FBI, but this is more than balanced out by his tendency towards {{Villainous Breakdown}}s whenever things go against him and his general slimy, arrogant know-it-all demeanour.
** Simmons, the drug lord Beckett brings in to ask about her mother's murderer in "Knockdown". [[spoiler: He actually gets her angry enough to throw him against the interrogation mirror and cracks the hell out of it, not to mention nearly goading Castle to a fistfight.]]
** The little bastard from "Hedge Fund Homeboys". Both Castle and Beckett really, really want to take that punk down.
** The prime suspect in "Undead Again" even wants to fill up a comment card for the level of service he received while being held inside the precinct.
* SniffSniffNom: In "Murder Most Fowl" Castle finds a feather in the victims pocket, sniffs it, licks it and then declares that it's from a bird of prey. He also concludes that therefore, the man must have been killed by the nefarious [[EpilepticTrees "Falcon Killer"]].
-->'''Castle:''' Struck down by a killer with the speed and cunning of a bird of prey.\\
'''Everyone else:''' (''incredulous look'')\\
'''Beckett:''' Don't ask.
* SoCalization: In "The Third Man", in Alexis' jealousy over her father's attention, she mentions that her classmate wants him. She then says that she's seventeen, "but she'll be legal in three months!" The age of consent in New York is seventeen.
* SomethingElseAlsoRises: In the beginning of "The Human Factor" Castle is using a camera on an RC tank toy to peep at Beckett while she's in her undies. He makes the tank's main cannon rise along with the camera.
* SortingAlgorithmOfMortality: Lampshaded by Ryan to Esposito in "Under The Gun" who comments that because Esposito is snarky and Hispanic, he'll definitely die first. Castle tries to lampshade it but Beckett cuts him off.
* SoundtrackDissonance: In quite a few intros where the camera pans down to a corpse, relatively light music can be heard playing the background. Especially dissonant in the intro to "Home is Where the Heart Stops" with that cheery little pop playing as the camera slowly pans to the body.
* SpecialEditionTitle: "Countdown"'s title sequence is simply the logo, unanimated and tinted blue, to prevent MoodWhiplash.
** "Kick the Ballistics" has the logo in normal colors, but no cheery music, again to prevent whiplash.
** "Demons" has a Halloween special version of the intro, with the piano music played via OminousPipeOrgan and wolves howling.
** "The Blue Butterfly" has the tune played in sax, jazz style.
** "Always" has the logo in slighly greener tones, without cheery music.
** "Swan Song" features an rock version of the theme tune.
** "Secret Santa" gives us a Christmas-themed version, not unlike the ''HomeAlone'' title music.
* SpecialGuest:
** Joe Torre, a baseball player and manager, who appears in "Suicide Squeeze". Castle is fairly nonchalant, having met Joe before and not being overly interested in the game anyway, but Beckett can barely keep from {{Squee}}ing and immediately rushes off to call her dad to gloat.
** Chef Rocco Dispirito appeared in "Food to Die For" during Castle’s date with Beckett's high school BFF.
** Gene Simmons shows up in "To Love and Die in LA" as a friend of Mike Royce's.
** Castle calls Wes Craven in "Scared to Death" for help on a scary case.
* SpitTake: In ''Nikki Heat'', Beckett sprays her coffee in reaction to Natalie's question [[spoiler: "Is Castle gay?"]]
* SpoilerOpening: Averted in "Probable Cause". Since most astute Castle viewers know that [[spoiler:actor Michael Moseley plays Jerry Tyson, AKA 3XK]], that particular credit is ''not'' in the normal opening guest credits.
* SpousalPrivilege: In "Den of Thieves", they interview the wife of Esposito's allegedly-DeadPartner, whom they suspect of the murder. She points out that either he's really dead, in which case he didn't do it, or he's not, in which case they're still married and she can't be compelled to testify against him.
* {{Squee}}: What Beckett tries (and partially succeeds) at holding in when she meets "Joe Frickin' Torre" in "Suicide Squeeze".
-->'''Beckett''': I gotta call my dad! ''[disappears offscreen]''
* StabTheScorpion: A double StabTheScorpion. Beckett and Castle are facing each other, both apparently pointing guns at the other. They fire simultaneously, and both hit a bad guy that was sneaking up to take the other unawares.
* StalkerShrine:
** Castle's obsessive fan in "Flowers For Your Grave" possesses one of these, which goes a long way towards putting the nails in his coffin when it comes to his guilt. [[spoiler: Subverted, in that he actually ''didn't'' do it.]]
** [[strike:Beckett]] Nikki Heat's obsessive fan in "Boom!" has one as well, complete with creepy [[strike:Beckett]] Heat collage and manuscripts about killing [[strike:Beckett]] Heat.
** In "Inventing the Girl" the victim's stalker does ''not'' have one of those, [[spoiler: since he was not an actual obsessive stalker, but just pretending, in order to scare the victim into dropping out of the competition]].
* StartToCorpse:
** Zero in season 1 (the first shot of each episode was the corpse); not too much longer after (with a ''Series/LawAndOrder'' cold open to start each episode.)
** Slightly extended in "Wrapped Up in Death," the first Castle episode to show the victim [[strike:shortly before his murder]] actually being murdered by a sawed-off gargoyle head, then cut away to Castle's home antics, then back to the crime scene.
** Extended a bit longer in "The Late Shaft", wherein the opening is Rick Castle going on a late night talk show, then the next morning finding out the host is dead. [[spoiler:In fact, it's ruled natural causes at first, but the host told Castle that someone was trying to kill him the night before, so he insisted Lanie take a look at it.]]
** Season 5 episodes have extended this, often showing the murder or the events leading up to the murder before the main characters make their appearance.
* StatusQuoIsGod: Every so often, Captain Gates will start warming to Castle slightly, or they will discover some mutual interest or commonality. If this happens, expect something to happen in order to crush this budding friendship and leave Gates, if possible, hating Castle even more than she did previously.
* StealthHiBye:
** "Home is Where The Heart Stops" [[spoiler:Powell pulls one while standing about a foot away from Castle.]] Spoilered not to ruin the awesome.
** In "Fool Me Once", the scary CIA agent does the same.
** In "Knockout", [[spoiler: Castle does this to Beckett on request from Montgomery.]]
** In "Scared to Death", a motel owner does this to Beckett and Esposito. Hilariously, Esposito is startled and backs against a wall.
* StealthPun: ''Castle's'' most popular character is Derrick ''Storm''. As in StormingTheCastle.
* {{Steampunk}}: Castle and Beckett visit a Steampunk club in Season 3's "Punked." And it's ''awesome''.
* StrangersOnATrainPlotMurder: "The Double Down." Both the movie and the original book are referenced. In this case, the strangers were on a boat.
* StuntCasting:
** From "A Rose for Everafter", NewOldFlame Kyra Blaine, played by Alyssa Milano. Oh, and Sophia Turner, played by Jennifer Beal in the season 4 two-parter "Pandora"/"Linchpin".
** The two-episode arc, "Tick, Tick, Tick" and "Boom" has ''DesperateHousewives'' Dana Delaney as a federal agent. NathanFillion previously played Delaney's husband on that show.
** "The Late Shaft" features Tom Bergeron, who just happens to host ''DancingWithTheStars'', ''Castle'''s lead-in.
** Averted with Beckett's dad, who's just a regular character actor and even matches the photo shown in passing during the first-season.
** Lyle Lovett as a member of TheMenInBlack in "Close Encounters of the Murderous Kind".
** Adam Baldwin in "Headhunters". The ABC press release prior to the episode made gratuitous mention of his past in Firefly, the beloved but short-lived show with Nathan Fillion. Baldwin also did numerous interviews promoting his one-episode part before the show aired.
** Another of Nathan Fillion's co-stars from ''{{Series/Firefly}}'', Gina Torres, appears in "Reality Star Struck".
** Jackson Hunt in "Hunt", played by none other than [[spoiler:James Brolin]].
* SuperstitionEpisode: In the episode "Wrapped Up In Death", Castle becomes convinced he's been cursed by a Mayan mummy from a museum exhibit after he opens its sarcophagus and looks upon its face. The precinct razzes him about it ([[spoiler:removing bolts from his chair so it collapses, then having the bomb squad rig the coffee maker to spew steam at him]]), but when the elevator stops working with Castle inside it, they tell him even they're not that cruel. He gets the curse lifted [[NoodleIncident somehow]] by the end of the episode ... then cuts himself with a bread knife.
--> '''Castle:''' What's the difference between "curse" and "clumsy"?
* SupportingProtagonist: Despite being the eponymous character, Castle is clearly this to Beckett. Looking at the tropes, ''he'' is the zany sidekick and ''she'' is the hardboiled detective who'd be the star of any other show. And the SherlockHolmes comparisons abound: Castle finds Beckett, realises that she's a brilliant detective, all but attaches himself to her hip and then writes about their adventures in crime-solving.
** However, the show operates on two levels. In addition to crime-fighting, the relentless {{UST}} between Castle and Beckett also prompts major character development from Castle. Even as he's the plucky sidekick in the cases, he's the main character in his transformation from playboy to heroic figure.
* SureLetsGoWithThat: Seemingly played straight in "A Rose For Everafter" where Beckett accuses Castle of messing with her chair while Castle thinks she's talking about him seeing the suspect behind her back. Castle thinks he's in the clear when Beckett shows that she knows about that too.
** In "Swan Song", Gates calls Castle and Beckett into her office, where they think she's gonna tear them a new one about their relationship being caught on camera by the documentary crew that followed them around all episode. Turns out she's gonna tear them a new one for photobombing her very serious mug for the documentary camera.
** Happens again in "Reality Star Struck" between Castle and Gates, when in an attempt to surprise Beckett with his Valentine's gift to her, he accidentally slips it into Gates's blazer instead. Thankfully for Castle, the note he leaves inside the gift box doesn't mention Kate by name, so Castle easily agrees with what Gates thinks is a practical joke at her expense.
* SwitchedAtBirth: [[spoiler:The ending to "When the Bough Breaks." And it's a TearJerker.]]
* [[TagAlongActor Tag Along Author]]:
** The premise of the show, with Castle shadowing Beckett for research and inspiration for his Nikki Heat novels.
** Also invoked in-universe with an actual actor when Natalie Rhodes spends a case shadowing Beckett in "Nikki Heat".
** Invoked again, when writer Alex Conrad (Castle's protege) starts meeting with Beckett in "The Dead Pool".
** And yet ''again'', in "Heroes and Villains", when Paul Whittaker turns out to be a journalist shadowing costumed superhero Lone Vengeance. [[spoiler:Except that he's also her lover.]]
** Averted in "Ghosts". Ghostwriter Lee Wax tried to arrange an all-access pass with Castle. But when Castle figured out that [[spoiler: Lee Wax had intentionally leaked the identity of the subject of her book, hoping that her arrest would be good PR for her book and give her artistic freedom to write it her way,]] her all-access pass was ''revoked''. And to add insult to injury:
--> '''Castle:''' Oh, and one more thing; one day, and one day not very far from now, I'm gonna use this in a book.
* TagalongKid: Sometimes Alexis. She's smart and mature and all that, but still unquestionably a kid. And on those occasions when she shows up at the precinct, everyone's on their best behavior.
** In the latter half of Season 4, starting with "Pandora", she interns for Lanie, and participates at times whenever the cops require Lanie's expertise.
* {{Tagline}}: In-universe example in the episode "The Late Shaft", Castle decides he and Beckett need one. He first tries "She's armed, ''he's'' dangerous" without success, then...
-->'''Castle''': How about: "A whole new ''chapter'' in crime-solving". [[IncrediblyLamePun "Chapter"]], [[DontExplainTheJoke get it?]]\\
'''Beckett''': Ooh! ... No.
** The second was the tagline on the Season 1 DVD set, while the first would become Season 2's DVD tagline.
* TakeAThirdOption: A dog, of all things, gets to do this in "An Embarrassment of Bitches" when, given the choice of living with Castle or Beckett, who have been sharing responsibility of taking care of him, [[spoiler: he instead chooses to live with Kay Capuccio, much to their mutual disappointment.]]
* TakeMyHand: In "Always": [[spoiler:Ryan, with a bunch of police officers, rescues Beckett just as her hand slips from the roof of the building she was hanging off of... while a scowling Gates looks on, ready to rip Beckett a new one.]]
* TakeThat:
** In "Little Girl Lost", we have this exchange between Beckett's ex-boyfriend and Castle.
---> '''Sorenson''': Why the sudden need to shadow a real detective ? \\
'''Castle''': Well the ones on TV seem [[CSIMiami mighty fixated on their sunglasses]].
** In the episode "Wrapped up in Death" a archaeologist at a museum is killed and an ancient Mayan mummy curse is blamed. Not much later this happens:
-->'''Castle:''' This guy is like IndianaJones but with space age technology. Oh, which would have been such a better movie than that last one.
** In "Sucker Punch", Beckett mentions that the Captain's post-incident evaluation [[spoiler:where they confront the guy who killed her mom]] has Castle come off like StevenSeagal.
--> '''Castle''': Should I be flattered or insulted?\\
'''Beckett''': {chuckle} Both.
** From "Target":
--> '''Beckett:''' Why would he shoot at the van?\\
'''Castle:''' Maybe [[Series/{{TwentyFour}} Jack Bauer]] was driving.
* TakingYouWithMe: How [[spoiler:Captain Montgomery]] ends season three.
* TemptingFate: A hilarious one in the pilot, no less. Castle is talking to Alexis, telling her he wishes for someone to come to him and say something new. When Beckett appears and tells him she wants to question him about the killings by someone who is making his killings look like Castle's books, Alexis [[LampshadeHanging lampshades]] the whole thing.
* TenMinuteRetirement: "Sucker Punch", of a sort; [[spoiler: when Beckett discovers that the murderer of the week was the same person who killed her mother, pretty much her first impulse is to flee the station.]]
** At the end of "After the Storm", [[spoiler:Beckett is reinstated by Gates, but still has to serve her suspension along with Esposito]].
* TenPacesAndTurn: "Punked". [[spoiler: This conveniently covers up the circumstances behind what really killed the episode's victim]].
* ThatCameOutWrong:
** This brief pip from "The Final Nail":
-->'''Castle''': Do I see two men jumping on a hot workman-related lead? That sounded dirtier than I thought.
** One slightly different instance in "Almost Famous". Castle talks about pumping Manschaft until he pops. There are very quick cuts showing reaction shots before the scene moves on. Though from Castle's tone, it's more a matter of GettingCrapPastTheRadar.
** From "Secret's Safe With Me", as Beckett, Ryan and Esposito confront a suspect cutting into a safe with a welding torch:
-->'''Beckett:''' Take your hand off your tool, Marco!\\
''[Ryan and Esposito snigger immaturely]''\\
'''Beckett:''' ... Shut up.
** In "Still" after Castle reviews a number of examples of Beckett's supposedly inappropriate comments in the work place:
-->'''Beckett:''' That's not how I meant it. I can't help it if you get off sticking things in my mouth.\\
'''Castle:''' See, like that. I can't even - I can't
* TheBigDamnKiss: [[spoiler:At the end of "Always", Beckett and Castle ''finally'' have their long-awaited, well-deserved kiss.]]
* TheKillerWasLeftHanded: clues Castle in that the case isn't over.
* TheTease: Beckett takes great amusement in leading on Castle's obvious attraction to her, only to bluntly shoot him down. Lampshaded in "The Mistress Always Spanks Twice":
-->'''Castle:''' You should really moonlight [as a dominatrix]. Trust me -- you would make a ''fortune''. Come on, isn't there anything you would like to do with your handcuffs besides arresting criminals?\\
'''Beckett:''' No...''[seductively]'' but there is one hot, wild, ''kinky'' thing that I do like doing...\\
''[Castle's elbow slips off the table as he stares at her earnestly]''\\
'''Beckett:''' ''[Flatly]'' Putting killers behind bars.\\
'''Castle:''' ''[Disappointed]'' See, you're already a tease — you're halfway there.
** Turns against her in "47 Seconds" when [[spoiler:Castle learns that Beckett remembers everything he said when she was shot, and comes to believe that it really is all just a joke to her]]. For the next few episodes, Castle distances himself from her, leaving her to wonder what she did to deserve his treatment of her.
* ThemeTuneCameo:
** In "Home is Where The Heart Stops", Castle is [[WaitHere sitting alone in the car]] humming ''his own'' action-scene {{Leitmotif}}. When the bad guy shows up to hijack the car and drags Castle into a fistfight, he stops humming and the leitmotif [[Funny/{{Castle}} starts playing over the scene]]. After the suspect is caught, he hums it again off-screen, only for Beckett to shut him up.
** When Castle walks into the The Old Haunt in "Last Call", the bar's piano player starts playing that leitmotif again. Castle even thanks the piano player for remembering and tips him.
** This also comes up in one of the "musical stings" that Castle uses to end a scene in "Swan Song".
* TheyFightCrime! He's a lecherous mystery novel writer! She's an uptight police detective!
* ThisIsForEmphasisBitch: In ''The Final Frontier'', the washed up alcoholic captain from ''Nebula 9'' gets held at (deadly) laser gunpoint by a former costar who betrayed and shot him in show, but elbows his captor, grabs and flips her forward, then grabs the gun and says:
--> '''Gabriel:''' I've been waiting ten years to do that, bitch.
* ThoseTwoGuys: NYPD detectives Javier Esposito and Kevin Ryan that Kate works with. It wasn't until "When the Bough Breaks" (the fifteenth episode) that we saw those two apart for even a ''moment''.
** Not quite true -- since Ryan wasn't originally supposed to be a character, there are some moments in the pilot when Esposito is walking around with some other random detective. Ryan's absence is VERY noticeable when you re-watch it after a few other episodes.
** In "The Blue Butterfly", they play ThoseTwoBadGuys in the flashbacks (Castle's imagination as he reads a diary from the 1940's).
* TimeBomb: "Countdown" [[spoiler:has a dirty bomb with a timer set to go off in New York. Castle and Beckett find the bomb with less than 2 minutes. They send a cell phone picture of the bomb to an expert, but he can't get the pictures in time on his cell. Castle and Beckett brace for the explosion, only for Castle to yank all the wires with the timer reaching 0. No boom.]]
** In "Still", [[spoiler:The pressure bomb Beckett steps on also turns out to be a time bomb, with a 5-letter password. The gang figures out that it's supposed to be the name of the killer's son, who was born while he was in prison. With 5 seconds left. No boom. She can leave.]]
* TitleDrop: Episode titles are dropped quite often, because they either would make great names for Castle novels, or already are great names for Castle novels.
* [[spoiler:TokenMinorityCouple: Lanie and Esposito as of "Poof! You're Dead."]] Except for an offhand lewd remark in one episode, there is no buildup to this which is lampshaded by several jokes in the vein of "Can you believe they still think we don't know?"
* TonightSomeoneDies: Promos for "Knockout" used a Castle line "One of them is gonna die." [[spoiler:Though it's only a tangential line (Castle was actually referring to the possibility of Beckett and Lockwood having a confrontation), Captain Montgomery ends up going out in a blaze of glory.]]
* TooSoon: The episode "Still", which features Beckett being caught on top of a pressure-sensitive bomb, was pushed back one week following the Boston marathon bombings (and the Boston ABC affiliate elected not to air it even after it was pushed back). TNT failed to get a repeat of "47 seconds" (another bomb plot) out of its Wednesday rotation and later apologized.
* TragicKeepsake: "A Chill Goes Through Her Veins" reveals that Beckett wears her mother's wedding ring as a reminder of "the life I lost". Also inverted, in that she ''also'' wears her father's watch to remind her of 'the life I saved'; she helped him recover from alcoholism and grief after her mother's death broke him. Because the latter's more visible (and unusual), Castle mistakes it for the former.
** Beckett shows Castle another one in "Secret's Safe With Me", a stick-figure doll that she and her father made out of odds and ends at the beach where they went for a walk during her mother's funeral.
--> '''Castle:''' Does that day make it a bad memory or a good memory?\\
'''Beckett:''' Both. It's a reminder that even on the worst days, there's a possibility for joy.
* TranquilFury: Beckett in "Probable Cause" in the final confrontation with [[spoiler: Jerry Tyson a.k.a 3XK]], after a brief gunfight, she ends up stalking towards his car firing shot after shot into it[=/=]him with a terrifyingly blank expression on her face, [[TheTerminator Terminator-style]]. Apparently she didn't appreciate the whole 'frame Castle for both cheating on her and murder' thing he was responsible for.
** Castle in "Target", when facing down an accomplice to [[spoiler: his daughter's kidnapping]]. He turns from helpless and worried to cold and vengeful literally in the blink of an eye.
* TreacheryCoverUp: The team agrees to hide [[spoiler:Captain Montgomery]]'s shameful past after [[NeverSpeakIllOfTheDead his]] [[HeroicSacrifice death]] at the end of the third season.
* TheTriadsAndTheTongs: The team's investigation of 3XK in "Kick the Ballistics" leads them to a Tong. Beckett mentions that most Tongs are legitimate merchant organizations but a few are involved in criminal activity.
* TriangRelations: It starts with a Type 5 in "Den of Thieves," [[spoiler: Type 4 with Castle being A and Beckett and Demming taking up B and C at the end of "Overkill"]], and either Type 4 [[spoiler: with Beckett being A, Castle being B and Gina being C]] or Type 10 [[spoiler: with Gina being A, Castle being B, and Beckett being C]] at the end of the Season Two finale.
* TrouserSpace[=/=]VictoriasSecretCompartment: In "Home Is Where The Heart Stops", Beckett has to make an arrest while at a black-tie event, wearing a rather [[{{Fanservice}} skimpy]] dress.
-->'''Castle:''' Where was the badge?\\
'''Beckett:''' Don't ask.
* TrueCompanions: Settled in the third season finale:
-->'''Beckett, to Ryan, Esposito, and Castle''': No one — no one outside of this immediate family, ever needs to know about this.
* TruthInTelevision: The fifth season episode, "The Fast and the Furriest" was right about chimps. Full grown chimps are stronger than world-class weightlifters and are territorial and aggressive.
* TurnInYourBadge:
** Though no actual badge-turning occurs, Montgomery sends Beckett home after she roughs up a witness in "Knockdown". Then he sends Castle home, too.
** Fallon does something similar in "Setup."
** In the episode "Always", [[spoiler:Gates has Esposito and Beckett turn in their badges for withholding evidence and lying to her. Beckett tells her to keep it as she's resigning.]]
* TwerpSweating:
** Averted in "A Death In The Family" -- Castle wants to scare Alexis' date with a fake severed head, but she cuts him off at the pass. Lampshaded in the same episode when Castle and Ryan reminisce about the ways the fathers of their prom dates had done this, leaving the previously clueless Beckett to come to the dawning realisation that this was what her dad was doing when she was upstairs getting ready for her prom.
--->'''Beckett:''' Now that you mention it, he looked ''terrified''. And this whole time I thought he was scared of ''me''.
** Castle later pulls this off pretty well, mostly by accident, in "Punked." He [[spoiler:storms in with an antique dueling pistol and demands to know who is sullying his honor. Unbeknownst to him, Alexis and her boyfriend are making out at the time.]]
** A deleted scene from season 3 has Jim Beckett inadvertently do this to Castle. [[http://www.youtube.com/watch?v=pPUnxxZ2L4s And it is magnificent.]]
** Lampshaded in a conversation between Castle and Beckett at the beginning of "Recoil":
--> '''Beckett:''' So what makes you so sure that Alexis isn't serious about this guy?\\
'''Castle:''' Well, I haven't met him or approved of him yet, so I can't be certain. All suitors must be met and intimidated by me, personally, before they can be considered for official boyfriend status.
* TwinSwitch: A rather big key to the plot of "A Dance With Death". Difficulty: the women who switched weren't even related; [[spoiler:a woman who worked as a stripper was given money by an heiress to get plastic surgery to appear at events as her double. Then the heiress is killed in a train accident, allowing the stripper to assume her identity full time, fooling everyone...except the heiress' manager and former boyfriend, who killed her for assuming the identity.]]
* TwinThreesomeFantasy: An actress who has been studying Beckett in order to better portray Nikki Heat (in the episode of the same name) gets a delivery that's "supposed to help with [her] research," then goes to change. A couple of scenes later...
-->'''Beckett:''' I contacted other precincts to find out who else is investigating her and for what.\\
'''Rhodes:''' (''walks into the room with Beckett-styled wig and pantsuit'') Talk to enough people, something usually shakes out.\\
'''Castle:''' (''[[DramaticDrop pencil falls out of hand]], as Beckett stares at Rhodes'') Just like I dreamed it...!\\
'''Beckett:''' (''[[DeathGlare GLARES at Castle]]'')\\
'''Castle:''' ...[[DidIJustSayThatOutLoud Did I say that out loud?]]
* TwoLinesNoWaiting:
** Subverted in "The Double Down", it seems as though two investigations are going on at the same time, but then [[WorkingTheSameCase they turn out to be connected]].
** "The Fifth Bullet", as well, although it takes all of five minutes for them to connect [[strike:Riley]] Amnesia Guy to the murder.
** "After the Storm" has Ryan enlisting Castle and Beckett to find Montgomery's friend, while Esposito tries to identify Beckett's shooter. They run into each other later inside the building where the shooter tries to find the incriminating files against his employer.
* TyrantTakesTheHelm: In comparison to Montgomery, Victoria "Iron" Gates fits this trope to a T.
* UnclePennybags: Though used variously in the earlier seasons where Castle would use his wealth and influence to do something, as of the later seasons, this aspect of his character has been heavily downplayed. Likely due to the show really hitting its stride and not needing such exaggeration.
** Still referenced in Season 4; when Castle first reads the bill for his actions during "Eye of the Beholder", his only response is to say it's "a good thing he's rich".
** In "Secret's Safe With Me", Castle commonly carries $2,000 cash and is only excited about potentially finding the expensive stolen bracelet; even though he knows he can't keep it and already has plenty of money, he's just excited about the thrill of discovery.
* UndercoverModel: In "Deep in Death", Kate Beckett does this on the fly around Russian mobsters. More specifically: she ditches all her clothing save for (bright red) underwear and a cardigan, which she wears as an improvised dress showing lots of leg and AbsoluteCleavage.
* UndyingLoyalty: "Knockdown" makes this almost painfully clear.
* UnrequitedLoveSwitcheroo: Seems like every third episode, now. Just as Beckett gets over Demming, here comes Castle's ex-wife. And just as Castle's done with his ex-wife, here comes MartyStu Josh.
** On a broader scale: Season 3 highlights Castle's one-sided feelings for Beckett, where for most of the season, Beckett is with Josh. Somehow, this doesn't keep him and Beckett from [[spoiler:kissing one another just to distract a guard, as well as getting locked in a freezer and nearly dying together]], two events which leave Castle wondering where the both of them stand. Season 4, on the other hand, shows Beckett pining more for Castle than the other way around, as Castle is [[spoiler:(for most of the season, at least)]] thinking that Beckett is unaware of his feelings for her, while she somehow keeps expecting him to act on those feelings, which she doesn't admit to knowing. The extent to which she expects Castle to do something about their relationship is shown in her occasional therapy sessions, the only place where she's a lot more honest about her feelings (yet still continues downplaying them).
* UnspokenPlanGuarantee: "Hunt" has Castle and [[spoiler: his father]] plotting an assault on the building where Alexis is being held. We first see them planning to take out the electricity by planting a bomb, only for Castle to get caught doing so. [[spoiler: Only after Hunt announces to Volkov "You'll be dead" is it revealed that they planned for that to happen, as the scene cuts to a flashback of the full plan]].
* UptownGirl: A gender-inverted example; the series is essentially about a millionaire (Castle) and a working-stiff police officer (Beckett) falling in love with each other.
* UrbanLegendLoveLife: Despite the claims of his TheCasanova charms, Castle has had sex or relationships with surprisingly few women during the show.
** However, it's a plot point that he's [[{{UST}} interested in Beckett]] very soon after they met, so even though they're not an official couple, he isn't pursuing other women as much during the show as he used to and is more likely to reject their advances. Many characters in the first few seasons mentioned him being more serious about their working relationship than he was about previous ''actual'' relationships.
** Conversely, Beckett is shown or mentioned to have dated a number of men; more than Castle has dated women. While this doesn't necessarily translate into a love life (since it's also mentioned she doesn't really connect with people well), it's suggested that she intentionally self-sabotages relationships by dating for the short term and dating people she knows aren't ultimately compatible. Refreshingly though, the show makes no comment on the matter of sex and romance for a female lead and simply treats it as the activities of a normal adult.
* {{UST}}:
** The show manages to up the ante on shows like ''TheNanny'' and ''Series/{{Bones}}'' by having Castle more or less repeatedly go to Beckett "So! When are we sleeping together?"
** In 2x13, "Sucker Punch", Beckett refers to Castle "pulling her pigtails" [[spoiler:and admits that she likes it.]]
** In 2x14, "The Third Man", ends with Castle and Beckett walking out of the police station arm-in-arm to head to a burger joint after their fancy dates (with other people) fall-through due to the case-of-the-week. As they walk, [[{{Squee}} Beckett is playfully twirling her hair with her finger, something that Castle had noticed her doing earlier while talking to her date on the phone.]]
** 3x05, "Anatomy of a Murder", had Castle comments to Esposito about how true friends will help you break out of jail. Beckett casually walks by and comments that she'd spring him, and the look on Castle's face is absolutely ''priceless''. Also, the LoveLetterLunacy played for epic amounts of ShipTease in the same episode... GAH!
*** Castle's reaction to Beckett's comment is much bigger than what it looks like, because his mother told him before that breaking a loved one out of jail was "true love".
** 3x11, "Nikki Heat", has a WithThisRing moment where Castle casually offers an engagement ring [[spoiler:belonging to Ryan]] to Beckett and asks her to marry him. Subsequently, an actress studying Beckett to portray Nikki Heat [[LampshadeHanging hangs the biggest lampshade ever]] as she spells it out, word-for-word, to Beckett:
--->'''Rhodes:''' I don't get it. He's into you, but [[{{Tsundere}} you're determined not to give into these feelings]] [[EveryoneCanSeeIt that you clearly have for him]], so he [[AuthorAppeal fantasizes about you through his writing]]. It's ''literally'' verbal masturbation.
** 3x13, "Knockdown". The guys bring a GenreSavvy SmugSnake into the interrogation room. Aside from being entirely unflappable, he figures out Castle likes Beckett within ''seconds''.
--->'''Simmons:''' He's sweet on you. Makes him brave.
** 3x21, "The Dead Pool". Castle confesses his jealousy when Beckett [[DoesThisRemindYouOfAnything starts spending time with another writer]].
--->'''Castle''': Yes. Fine, it's true. I'm jealous. There, I said it. I-I want you all to myself, and to have you spending time with another writer? That upsets me! And if that makes me petty, so be it. Guilty as charged.\\
'''Beckett''' (smiling) : Actually, I kinda think it's sweet.\\
'''Castle''': You do?\\
'''Beckett''': I do. And that's why you don't have to worry about me hanging around with Conrad anymore. From now on I'm a "one writer" girl.
* VanityPlate: In a rather touching tribute, the show used the late StephenJCannell's VanityPlate at the end of "Punked".
* VehicleVanish: In "Dial M for Mayor", Castle meets with his mysterious informant in a parking garage. A car passes between the two of them, blinding Castle with its headlights. When it has passed, the informant is gone.
* VigilanteMan: Seemingly, the murderer in "Heroes and Villains" [[spoiler: but subverted when it turns out that it was a mob boss impersonating the vigilante in order to kill two birds with one stone - offing his traitor and getting the vigilante arrested]].
* VoiceoverLetter: See DeadManWriting [[Castle/TropesAToD section]].
* WackyParentSeriousChild: Richard (and Meredith) to Alexis, and to a slighter extent, Martha to Richard.
* WaistcoatOfStyle: Ryan just isn't Ryan without that third piece in his three-piece suit.
* WaitHere:
** Castle, natch. Happens so frequently that it borders on RunningGag. The few times where Castle listens and does stay, the bad guy runs by him or otherwise gets Castle involved anyway.
--->'''Kate''': You're staying here.\\
'''Castle''': Yes, we've seen how well ''that'' works out.
** There's also the time in the pilot when Beckett ''handcuffs'' him to the squad car, and he gets hijacked by the suspect.
** Subverted in "Boom!", in which Kate hands Castle a gun as they go to bust the killer, and Castle just stands there in disbelief for a second.
** Earlier in "Boom!", ''Beckett'' is told to wait in the van (since the killer is specifically looking for her):
--->'''Castle''': Now you know what it's like for me.
* WakingUpAtTheMorgue: The main suspect in "Undead Again" is found dead. This being a Zombie themed episode, Castle is wary of the corpse rising again...which it does, not two seconds after Perlmutter assured him that it wouldn't. He's not really dead, and how he got into that zombie like state is the crux of the rest of the ep.
* WealthyYachtOwner: Jimmy Wong, a minor character in the episode "Sucker Punch", claims in his infomercial that he came to America on a boat, and now "I own a boat!" [[spoiler: The second one may be true, but he's really from Danville, California and affects a Chinese accent to attract customers.]]
* WellDoneSonGuy: Both averted and subverted in "Hunt". Averted in that [[spoiler:when Castle finally does meet his father, he says that despite not being in Castle's life he was always proud of him.]] Subverted in that although [[spoiler:Castle]] never sought his father's approval, receiving it is obviously meaningful to him.
* WellIntentionedExtremist: [[spoiler: Senator Bracken, the man behind Beckett's mother's murder, believes himself to be this -- he tells Beckett in "After the Storm" that everything he's done has been to improve the lives of the needy. Beckett, whose mother was a casualty of Bracken's drive to be in a position where he can do this, naturally has a different view on the subject.]]
* WesternTerrorists: In [[spoiler:"Setup/Countdown" the villains turn out to be WesternTerrorists after teasing that they were Muslim extremists.]]
** In "47 Seconds", the chief suspect in the bombing of a Take Over Wall Street protest was a right-wing activist. [[spoiler: Turns out it was a reporter who wanted to use the bombing for fame, and a left-wing protester seeking to gain sympathy for his movement.]]
* WhamEpisode:
** "Sucker Punch", where [[spoiler: Beckett arrests, then has to fatally shoot her mother's hitman, destroying the best chance she had of finding out who ordered the hit.]]
** "Knockdown", where [[spoiler:the head officer on Beckett's mom's case is shot, Ryan ends up getting tortured by drowning and almost shot in the kneecaps, and the shooter (who is deeply involved with the conspirators responsible for Beckett's mother's murder) is incarcerated where Beckett can get to him.]]
** "Knockout", where [[spoiler:Lockwood escapes and murders the other cop implicated in Beckett's mother's murder, Captain Montgomery is revealed to have been with them as well and knows who TheManBehindTheMan is, both he and Lockwood kill each other, and at Montgomery's funeral Beckett is shot. Oh, and Castle finally tells her that he loves her. As she's slipping out of consciousness.]]
** "Always". Good God, "Always". [[spoiler:Alexis graduates high school, Beckett confronts the man who shot her, resigns from the police force, and tells Castle that the only thing she wants is him.]] Every constant this show has has just been turned upside down.
** "After the Storm". [[spoiler: We learn the identity of the man behind the various conspiracies the show has had going, including the murder of Beckett's mother -- namely, William H. Bracken, Senator for New York.]]
** "Probable Cause", despite being unrelated to the story arc of Beckett's mother's murder. [[spoiler: In the course of investigating a bizarre murder, all evidence points to Castle as the most likely suspect. He is arrested, and while in the holding cell, is visited by the real culprit, Jerry Tyson (3XK). Castle eventually escapes with Beckett, which leads to an apparently final confrontation with Tyson where Beckett shoots him repeatedly and he falls off a bridge. As the authorities are unable to locate his body afterwards, Castle is convinced that the entire thing was a setup to help him disappear for good and begin killing again]].
** "Recoil". What appears to be yet another murder tied to Senator Bracken -- [[spoiler: the one responsible for Beckett's mother's murder]] -- turns out to be that of a killer planning to murder the senator. Beckett encounters the very troubling dilemma of either doing her job and protecting the senator from the killer, or allowing the killer to succeed and finally getting revenge on the senator. Beckett ends up saving the senator's life, but doesn't get any closer to being able to take the senator down.
** "Target"/"Hunt". Alexis and a friend from school are kidnapped, and she gets in contact with her father after escaping. It's discovered that [[spoiler: she's in Paris, France and gets recaptured.]] Castle later uses his connections to attempt to find her on his own, and ends up being betrayed by the man he hired. He is saved, however, by a man who later reveals himself as [[spoiler: Castle's father]], and that everything that happened was a plot to draw him out. [[spoiler: The two of them succeed in saving Alexis, and Castle's father disappears again, but not before telling his son how proud he is]].
* WhamLine: In "Rise", Beckett tells Castle that she doesn't remember anything after [[spoiler:being shot]]. At the end of the episode, she tells her psychologist that she actually remembers everything that happened.
** In "Linchpin", "Your father will be very proud." [[spoiler:Said by the turncoat Sophia, to ''Castle''. Of course, since she'd just revealed herself to be a Russian double agent, it's probably all BlatantLies.]]
*** In "Hunt", [[spoiler:it turns out he is. Less a WhamLine than a CrowningMomentOfHeartwarming and TearJerker, but she wasn't lying. Just being a bitch.]]
** And again in 47 Seconds, where Beckett tells a suspect that claims to have amnesia that she [[spoiler:was shot "and remembers every second of it"]], with Castle listening behind the one-way mirror, in a moment of self-inflicted EngineeredPublicConfession. Castle becomes passive-aggressive the rest of the season, as a result.
** "Always". [[spoiler:"Beckett, what do you want?" "You."]]
** In "Target", after a kidnapped Alexis gets in touch with them, they track her location. [[spoiler: "That can't be right". "What? Why?" "It says the call's originating from a tower in Paris, France."]]
** "Hunt":
--> '''Castle:''' I don't understand. What does this have to do with Alexis? Why would they take her?\\
'''Hunt:''' Because I was careless. Because somehow he found out who she was, who you were, and he knew I'd come for her.\\
'''Castle:''' Why? Why would you come for her?\\
'''Hunt:''' Because she's [[spoiler: my granddaughter]].
** "Still": [[spoiler:"Oh, for heaven's sake, go ahead and kiss him already!"]] Did that not sound like one? The wham is in who said it: [[spoiler:Captain Gates]].
** Watershed: [[spoiler: "Katherine Houghton Beckett, will you marry me?"]]
* WhatTheHellHero: Martha deals one of these to Castle in "Knockdown," during a rare MamaBear moment.
-->'''Martha''': Richard, this isn't one of your books. You don't ''know'' the ending. You were just ''lucky'' yesterday.\\
'''Castle''': You're overreacting, mother. Where is this coming from?\\
'''Martha''': (''incredulous stare, tearing up'') How the hell can you ask me something like that? Think about how much you love Alexis and ''that'' is how much I love you and don't you ''dare'' ask me where this is coming from! (''calming down'') You have gotten through most of your life on your wit and your charm and no small amount of talent, but [[NotAGame that is the real world out there]]. And you can't ''charm'' your way out of a bullet.
** Again in "Knockout" with Castle calling Beckett out for her WillTheyOrWontThey behavior:
-->'''Castle:''' Alright, y'know what? I don't know ''what'' we are. We kiss and then we never talk about it. We nearly die frozen in each others' arms but we ''never talk about it''. So no, I got no ''clue'' what we are.
** Lanie calls Beckett out in "The Limey" for not telling Castle what she feels for him, and about the fact that she knows he loves her.
--> '''Lanie:''' Oh, what, was that supposed to be some big secret?\\
'''Beckett:''' Yes... (''Lanie glares at Beckett'') No... (''Lanie narrows her eyes'') Do you think he knows?\\
'''Lanie:''' You remember how he used to be? Girl on either arm? You really don't see that guy too much anymore; why do you think that is? He's waiting... for ''you''.
** In "Always", Castle calls Beckett out for keeping silent about the fact that she knew his feelings about her and never said anything in the entire year. In the same argument, Beckett accuses Castle of betraying her by keeping the fact that he'd been in contact with Mr. Smith and keeping his information secret, arguing that, regardless of the emotional issues she's been struggling with concerning her mother's case, she had a right to know. Needless to say, things get pretty heated and emotional on both sides.
* WhiteDwarfStarlet: Castle's mother.
* WhiteGangBangers: The Westies, an Irish gang in NYC, make multiple appearances, first in "Sucker Punch", and much later in "Headhunters".
* WildTeenParty: In "Heartbreak Hotel", Alexis watches in slowly growing horror as one of these takes place in her own home. In a variation, she acknowledges that her father probably won't care, but the problem is that ''she'' does.
** Alexis goes to one the night of her graduation, and returns home in "After the Storm" with a hangover.
* WillTheyOrWontThey: Definitely: Leaning towards "they will". And doesn't Castle know it. During one case they get asked if they're together, to which Beckett responds "No." Castle's simultaneous response? "Not yet."
** [[spoiler:In "Always", TheyDo.]]
* WireDilemma: [[spoiler:Averted]] in "Countdown". [[spoiler:Facing a dirty bomb with literally no time on it and nothing else to lose, Castle just [[CuttingTheKnot rips all the wires out of the triggering device]]. It works.]]
* WomenAreWiser: Played with; Alexis is a lot more grounded and mature than her father is, but compared to his ex-wives, and to a (slightly) lesser extent his mother, Castle himself is a bedrock of maturity, common sense and selflessness.
* WontTakeYesForAnAnswer:
** Variation in "Law and Murder": Captain Montgomery pulls Beckett and Castle in asking them why they pulled the DA's secretary in without the DA's knowledge. Beckett starts to apologize, but Montgomery cuts her off... with "Smart move." [[spoiler:Since the DA could have just called to demand his secretary back, but came personally to stop the questioning...which means he's probably hiding something.]]
** In “Knockout”, Beckett goes to Captain Montgomery to tell him [[spoiler:she wants Castle gone]], fully expecting to hear that it isn’t possible because of [[spoiler:his friendship with the mayor]], and starts vehemently arguing her case only to realize he agreed. Her flustered response is all the proof he needs that she wasn't serious and was just venting.
* WorkingTheSameCase: "The Double Down"... which does nothing to dull the wager on whether Castle & Beckett or Ryan & Esposito will solve their case first.
* WorthIt: Captain Gates is the no-nonsense type when it comes to police work. [[spoiler:But for the chance to chew out Castle and watch him squirm, she agreed to be part of the elaborate birthday surprise Beckett set up when Castle and Beckett "broke into" the suspect's storage unit.]]
* WoundedGazelleGambit:
** Done to Castle in "Love Me Dead". He finds it discomforting that someone could tell him a story and make him believe it and that someone was able to take advantage of his hidden heart of gold. Especially since the person doing the gambit [[spoiler: had killed two people.]]
** Also in "The Late Shaft", he floats Beckett's suspicion that an actress is only sleeping with him to get the Nikki Heat part in the ''Heat Wave'' movie, and she breaks down in tears. [[spoiler:She was (as well as doing the same with the head of Bobby Mann's network), but he still recommends her to the producers because she made him believe the gambit.]]
** Perhaps a BrickJoke as of "Nikki Heat" when we meet the actress who plays Nikki Heat in the movies. [[spoiler: It isn't the same actress. On the other head, she also doesn't get to sleep with Castle.]]
** In "Slice of Death", [[spoiler:the murderer does this to pin the murder on a more convenient suspect. She gets away with it until the very last second as she is leaving the precinct]].
** In "Cops and Robbers", [[spoiler:one of the hostages fakes an epileptic seizure to be taken out of the bank before the C4 bomb goes off. In truth, he was the one who planned the whole thing as part of a ploy to learn where his wife and son were hiding.]]
** In "Cuffed", one of the criminals [[spoiler:pretends to lock herself in a cage to lull Castle and Beckett into complacency before she can tranquilize them.]]
* WriteWhoYouKnow:
** Castle's new main character, "Nikki Heat," is Beckett. To the point that when Beckett showed up at his launch event, the photographers said "It's Nikki!" In the actual ''Heat Wave'', "Nikki" has ThoseTwoGuys on her team: Raley and Ochoa, usually combined to "Roach." And she's being shadowed by a writer (this time, a reporter) who pulled strings with the mayor's office to get himself attached to her. Named ''Jameson Rook''. Except Nikki and "Rook" had sex in the book -- Castle has less patience than his show's writers, it seems.
** In the episode "Boom", the FBI and NYPD teams find an autographed copy of ''Heat Wave'' that says, ''"To Scott: Write what you know."'' "What he knows" turns out to be [[spoiler: murders. Lots and lots of murders.]] The same guy [[spoiler:also turns out to be the killer.]]
* WrongGenreSavvy: Played for laughs.
** Castle likes to latch onto unusual facets of the case and build absurd plots out of them, when the truth is inevitably more straightforward:
** Castle spends the first few minutes of "Vampire Weekend" running around as if he's actually in a vampire movie.
** In "A Deadly Game", when "Hans Rowr" is arrested, he claims he'll soon be bailed out by powerful superiors to escape as a KarmaHoudini [[spoiler: because he's actually just a regular guy taking a 'spy vacation' and thinks the arrest is part of it. When he realizes he's actually blundered into a PoliceProcedural [=Murder-Of-The-Week=], he's... a bit teary.]]
** "Close Encounters of the Murderous Kind": Every single one of his theories points to aliens, and almost gets Beckett to believe it, too. [[spoiler:In actuality, it's a murder to cover up espionage]].
** In "Poof! You're Dead" Castle constantly -- and incorrectly -- assumes that various 'magic story' twists are in effect. [[spoiler: Such as his assumption that, on discovering that the victim had a twin brother, they've stumbled into an EvilTwin situation where one twin has murdered the other to steal his life (he hasn't), that a suspect in a wheelchair is faking his condition to cover up the crime (he isn't) or that a magician murdered the victim to prevent his tricks from being revealed (he didn't).]]
** In "One Life To Lose", a murder on the set of a soap opera leads Castle to come up with an endless list of over-the-top soap opera style plots as potential theories behind the crime. Which leads to this moment when he comes up with a more plausible one for once:
-->'''Beckett''': Wow, Castle, that's... a refreshingly down-to-earth theory.\\
'''Castle''': Just trying to keep you on your toes.
** "Once Upon a Crime" has a murder victim dressed as Little Red Riding Hood. Castle at first starts theorizing that she ''is'' Little Red Riding Hood, but after a while comes up with a decent explanation for the victim's attire, to which Beckett responds:
--> '''Beckett:''' Castle, that is a surprisingly reasonable and grounded theory.\\
'''Castle:''' Yeah. Frankly, I'm a little bit disappointed in myself.\\
'''Esposito:''' We all are, bro.
** In "Hunt", desperate after the case of his daughter's kidnapping has stalled, Castle takes it upon himself to fly to Paris to find and rescue her himself. Unfortunately, despite his desperation he hasn't actually become Liam Neeson in ''Film/{{Taken}}'' and remains a slightly wimpy milquetoast writer rather than a badass former spy, quickly finding himself out of his depth. [[spoiler: Which makes it rather fortunate that ''his'' father, and Alexis' grandfather, apparently ''is'' a badass former spy...]]
* WronglyAccused: Castle in "Probable Cause". [[spoiler:Framed by 3XK.]]
* XanatosGambit: [[spoiler: Jerry Tyler, aka 3XK]] pulls one off in "Probable Cause".
* XMeetsY: The episode "Swan Song" could be defined as {{Castle}} meets TheOffice.
* {{Yandere}}:
** In 1x02, "Nanny [=McDead=]", the killer ended up being [[spoiler:Chloe, who killed her friend because she was sleeping with Ian, and they were in love. Supposedly.]]
** In 2x16, "The Mistress Always Spanks Twice", the killer turned out to be [[spoiler: the codependent roommate, who didn't want the victim getting married (to someone else).]]
** In 3x12, "The Final Nail", the killer was [[spoiler:Simon Campbell's new girlfriend, who didn't want anyone getting in the way of her and her boyfriend's love.]]
* YouCalledMeXItMustBeSerious: Castle hardly ''ever'' calls Beckett by her first name; it's warranted only for a special, dramatic occasions.
** Once in "Sucker Punch," [[spoiler: when Beckett is fleeing the station after discovering the current case is linked to her mother's murder]].
** The second and third time happen during the two parter "Tick, Tick, Tick..." and "Boom!", [[spoiler: when Castle calls her to warn her moments before her apartment explodes]] and [[spoiler: as he searches for her in the flaming wreckage]], respectively. He also calls out her name a few more times (five more times, if you want to be precise).
** Once more in "Knockdown," [[spoiler: when Beckett leaves the department in a huff after Captain Montgomery dismisses her from a case linked to her mother's murder]].
** Beckett also calls Castle 'Rick' [[spoiler: in "Knockdown". As with the above examples, it's a serious moment where they're letting their guard down and before something particularly dangerous.]]
** And Castle calls Beckett 'Kate' [[spoiler: in 'Countdown' when she is passing out from the cold and they both might die.]]
** The 'Kate' and 'Rick' quotient is upped in "Knockout", culminating in [[spoiler:"I love you, Kate"...as she's in shock after taking a bullet from a sniper.]]
** Also occurs with... [[spoiler: Kate calling Captain Montegomery 'Roy' before his LastStand. It's significant because her other mentor, Mike Royce never gets called on a personal first name basis. Only her mother, father, and Castle get that treatment.]]
** During Rise, Castle ONLY calls Beckett "Kate". [[spoiler: Considering that he is still dealing with the fact that he confessed his love to her, it isn't surprising that he's acting emotionally familiar towards her.]]
** In "Kick the Ballistics", Castle calls Ryan by his first name once... at the end of the episode, when he is reassuring him about how he did the right thing.
** In "Kill Shot," Beckett calls Esposito "Javi" when he's trying to help her past her PTSD. She also calls him "Espo".
** In "Always," Ryan and Esposito call each other Javier and Kevin when Detective Ryan expresses concern that the team is following the wrong course of action.
*** Castle calls Beckett "Kate" almost throughout the entire episode, except for the last scene. The fact that [[spoiler:the person who hears Beckett screaming for help while she's hanging off the edge of a building ''doesn't'' call her "Kate" is one of the tip-offs that it isn't Castle. The other is that the hand that catches hers has a ring on it]].
** In "Still", Beckett calls Castle "Rick" for the first time in a good long while [[spoiler: when she tells him that she loves him, shortly before he's forced to leave her alone on top of the pressure bomb she's trapped on.]]
** Castle all ways calls Martha "Mother". At the end of "Hunt" he calls her "Mom". Presumably this leads to a serious off camera discussion about his father.
* YouDoNotWantToKnow: Inverted in "Heartbreak Hotel." Ryan and Esposito try to explain why they're wearing Elvis costumes, but Beckett decides she doesn't want to know.
* YouHaveOutlivedYourUsefulness: In "Cops and Robbers", [[spoiler: the bad guy of the week sabotages the C-4 of his mercenaries once their job was completed.]]
* YouHaveNoIdeaWhoYoureDealingWith: Beckett tries this in "Always". [[spoiler:Subverted in that the encounter ends with Beckett hanging off the side of a building, and the perp telling her, "Actually, we know exactly who we're dealing with." Which has a double meaning as they've found out just who the guy is that's protecting Beckett.]]
* YourMom:
** During the outtakes, Jon Huertas apparently screwed up his line and this happened:
-->'''Nathan Fillion''': You've got ''one'' line.\\
'''Jon Huertas''': Your momma has one line.
** Comes up again in "Knockdown", when [[spoiler: Ryan is being tortured and Esposito [[ForcedToWatch has to watch]]]]:
-->'''Esposito:''' OKAY!\\
'''Ryan:''' [[CrowningMomentOfAwesome Don't tell this jackhole anything.]]\\
'''Esposito:''' I'm sorry, bro, I can't watch this. (''to interrogator'') Listen to me! You're too late--the cops already know all about... [[CrowningMomentOfAwesome me and]] [[CrowningMomentOfFunny your mom]].
* YourPrincessIsInAnotherCastle: One of Castle's main skills appears to be spotting where these moments are coming up.
** He keeps investigating the case in the pilot precisely because his writer's sensibilities (along with those of JamesPatterson and StephenJCannell) are offended by the "easy" solution to the mystery (he even tells Beckett "the reader would never buy it!"). This occurs exactly half-way through the episode.
** In "The Mistress Always Spanks Twice," [[spoiler:it happens in the last 5 minutes of the episode.]]
** In "Boom!", he's able to sniff out a trap due to this very reasoning.
** In "Setup", Castle is pretty much the only one who believes that [[spoiler: the supposed Syrian terrorists are in fact innocent scapegoats being set up by a third party]], and Beckett the only one who'll hear him out. He turns out to be right.
** In "Slice of Death", [[spoiler:the drug kingpin behind all the murders is only caught at the last second as she leaves the police station.]]
** In a peculiar twist, Beckett is the one who has this realization in "Recoil". After the prime suspect is arrested for an assassination attempt on Senator Bracken, she realizes that the bomb that would have been used was expertly made, and that the mentally handicapped suspect could not have made that. She stalls the senator's keynote speech despite not having concrete evidence, and at the last second, is proven right and barely makes it in time to save the senator from the bomb in his limousine.
* ZanyScheme: Castle comes up with a fairly straightforward one in "Heartbreak Hotel." Results in Castle, Ryan, and Esposito sneaking into a casino from which they'd been barred in ''Elvis impersonator costumes.''
** Averted (kind of) in "The Limey". Castle's plan is outlandish even for Castle, but Beckett cuts him off with a ZanyScheme of her own. She'll get the fingerprints the easy way... by gatecrashing an exclusive dinner reception at the British Embassy.
* ZorroMark: In "Heroes & Villains", the vigilante Lone Vengeance carves an 'L' into the butt cheek of a mobster with a sword.