[[quoteright:350:[[Webcomic/{{XKCD}} http://static.tvtropes.org/pmwiki/pub/images/xkcd_707_edit_1.png]]]]
%%[[caption-width-right:187:future editors can add a witty caption of your own if you want. or, you know, just copy from the alt text]]

-> '''Doctor:''' Oh, Mr. Holmes, I would love to tell you, but then, of course, I'd have to kill you.\\
'''Sherlock:''' That would be tremendously ambitious of you.
-->-- ''Series/{{Sherlock}}'', "The Hounds of Baskerville"

[[SchmuckBait Tell me anyway!]]

Often heard in settings related to espionage and high security levels, the phrase "I'd tell you, but then I'd have to kill you" is itself probably a DeadHorseTrope by this point - whether for a serious straight use or not.

Nowadays used much more tongue in cheek to poke fun at [[ClassifiedInformation stern security protocols and classification]], it has started to show signs of decay since it's hard to pass off a StockPhrase as an original joke. Instead it's more common to get it as one character's joke to another, perhaps to demonstrate that character's lack of regard to the rigmarole of secrecy or mockery of the ''other'' character's clearance/understanding.

A common modern comedy subversion is to have one character say the phrase to another with the response "So it's classified?" they then answer "no, I just feel like killing you."

Compare JustBetweenYouAndMe, in which a BigBad tells the hero something they shouldn't before they attempt to kill them.

See the Supercut Mashup trailer of [[http://www.youtube.com/watch?v=VuE_jqYNi3c this line being said a bunch in films]].



[[folder:Anime & Manga]]
* Japanese speakers don't have this StockPhrase, but people like [[Anime/MobileSuitGundamWing Heero Yuy]] skip straight to "''omae wo korosu''" (literally "I will kill you") when people like Relena Darlian find out too much.
* ''Anime/GhostInTheShellStandAloneComplex: Solid State Society''. Paz says this to a {{mook}} in response to his WhoAreYou, and clearly enjoys every second of it.
* ''Anime/CowboyBebop'' episode Stray Dog Strut. Punch uses this line when his co-host Judy asks what a "data dog" is.

[[folder:Comic Books]]
* In the ComicBook/{{New 52}} version of ''ComicBook/ResurrectionMan'', Mitch asks a demon what he's planning, and gets the reply "I could tell you that, but then I'd have to kill you. [[ResurrectiveImmortality Repeatedly]]."
* [[{{Comicbook/Daredevil}} Bullseye]]'s Greatest Hits was a miniseries where Bullseye is incarcerated after stealing and hiding a batch of plutonium. The NSA sends a pair of agents to interrogate him, and he spends five issues [[CriminalMindgames messing with them]] and [[MultipleChoicePast telling them conflicting accounts of his life story]]. One of them finally gets tired of the game and asks him how he hid it.
-->'''Bullseye''': Okay, but you know the drill. If I tell you, I'll have to kill you.
-->'''Baldry''': That would be quite an accomplishment.
-->'''Bullseye''': Yeah. [[FingerGun It would.]]
* ''ComicBook/{{Planetary}}''
-->'''The Drummer''': So what's the plan.
-->'''Elijah Snow''': If I told you, I'd have to kill you.
-->'''The Drummer''': That joke is [[ReallySevenHundredYearsOld older than you are.]]
* Inverted in ''ComicBook/DeathVigil'': Sam is DeadToBeginWith, and Bernie only explains the secrets of the Vigil after Sam takes the offer to be revived.

[[folder:Comic Strips]]
* Said [[http://dribibu.xs4all.nl/dilbert20070902.html almost verbatim]] in a ''ComicStrip/{{Dilbert}}'' strip.

[[folder:Fan Works]]
* In ''[[https://www.fanfiction.net/s/10359113/5/Tempest-of-the-Fae Tempest of the Fae]]'' a goblin operating the mine cart Harry, Hermione and Luna ride in says "If I told you, you'd have to kill me." The stated rationale is that while it isn't ''technically'' illegal for them to be in possession of that particular information, offering it freely would count as treason.
* In ''[[https://www.fanfiction.net/s/4279293/3/Bleeding-Clown Bleeding Clown]]'' Harry and Snape communicate via two-way journal over the summer. Harry asks where Snape stays when he's not at Hogwarts.
-->'''Snape:''' In one of the Snape family manors, a highly unplottable location. If I told you, I'd have to kill you.
* ''[[http://archiveofourown.org/works/1935633/chapters/4180683 King's Jackal]]'':
-->'''Ginny:''' Can't talk in front of us?\\
'''Harry:''' I could, but then I'd have to kill you. It's super-secret stuff.
* In ''[[https://www.fanfiction.net/s/6982556/10/To-someone-who-is-as-fed-up-and-bored-as-I-am To Someone Who Is As Fed Up and Bored As I Am]]'' Harry asks a Muggle tailor in his neighborhood to make a robe according to a friend's design, claiming that it's for a costume ball.
-->'''Tailor:''' So which school do you really go to?\\
'''Harry:''' Hogwarts School for the Gifted. A small private school in Scotland. I would love to tell you more, but I would have to shoot you.

[[folder:Films -- Live-Action]]
* ''Film/TopGun''
-->'''Maverick''': We happened to see a [=MiG=] 28 do a 4g negative dive.\\
'''Charlie''': Where did you see this?\\
'''Maverick''': It's classified. I could tell you, but then I'd have to kill you.
* ''Film/AmericanPsycho''
-->'''Paul Allen:''' Well, Halberstram, I could tell you... but then I'd have to kill ya.
* ''Film/AWalkToRemember''
-->'''Jamie:''' I'd tell you, but then I'd have to kill you.
* ''Film/WolfCreek''
-->'''Mick Taylor:''' I could tell you. But then I'd have to kill you. [[spoiler: Which he then does with masterful skill]]
* Chris Farley's character uses this line on a little boy on a plane in ''Film/BeverlyHillsNinja'' and makes the kid cry.
* A variant in ''Film/TheLongKissGoodnight'': "If you want me to talk in front of him, you may be asked to kill him later."
* In the 2009 adaption of ''Film/ThePictureOfDorianGray'', Dorian quips this in response to being asked his secret of looking young.
* Agent One uses this is ''Film/JohnnyEnglish''. When Johnny himself tries it later, he gets the response "I'd like to see you try."
* Played with in ''Film/MenInBlack'': J tells Laura about the MIB. Then says "I'm sorry, I'm gonna have to...", to which Laura responds "Kill me." But just a little flash with the neuralyzer, and everything goes back to the way it was.
* The phrase appeared in one promotional poster for the hacker thriller Film/{{Sneakers}}.
* In the HammerHorror film ''These Are The Damned'' (1963), government scientist Bernard gives his mistress Freya the quote below. [[spoiler:He's not lying either, as he kills Freya at the end of the movie after explaining the project he's working on.]]
-->'''Freya:''' I hate your secrets, Bernard.
-->'''Bernard:''' If I were to tell you even a little bit about, what you call my secrets... I might be condemning you to death.

* In one of the ''Franchise/TheWitcher'' books, Geralt finds himself present during a sorcerous putsch, and the putchists capture him. Asking the leader what's going on, he is told sarcastically,
-->'''[[spoiler:Philippa Eilhart]]:''' Blessed are those who do not know, for they shall live a while longer.
* ''Literature/{{Discworld}}'': Vetinari (then a young assassin) in ''Discworld/NightWatch'' -- "I'd tell you but then I'd have to find someone to pay me to kill you."
* The first title of ''Literature/TheGallagherGirls'' series is ''I'd Tell You That I Love You But Then I'd Have to Kill You''.
* [[spoiler:Loki]] says this in ''Literature/AmericanGods'' - the Fat Kid [[GenreBlindness naturally]] [[SarcasticConfession assumes he's kidding]]. When the kid replies that yes, he really does want to know... he tells him. [[SubvertedTrope And then he kills him]].
* ''[[{{Literature/Dragaera}} Dragon]]'': "Were I to tell you matters pertaining to the internal politics of the House of the Dragon I should only weary you. And I would then have to kill you for knowing. So my thought was not to trouble you with such information."
* From ''Literature/TheThreeMusketeers'', [[spoiler:Athos]]: "Because I am believed to be dead, and have reasons for wishing nobody to know I am living; so that I shall be obliged to kill you to prevent my secret from roaming over the fields."
** An even more perfect example, from the sequel ''The Vicomte de Bragelonne'': "It's a state secret," replied d'Artagnan, bluntly: "and as you know that, according to the king's orders, it is under the penalty of death any one should penetrate it, I will, if you like, allow you to read it and have you shot immediately afterwards." (The secret in question is the identity of the ManInTheIronMask.)
* Used in its exact words by [[spoiler:Osiris]] in the last book in ''Literature/{{The Secrets of the Immortal Nicholas Flamel}}'' series.
* ''[[Literature/TheQuestForKarla The Honourable Schoolboy]]'' by Creator/JohnLeCarre - Ricardo explains his monologuing problem to Jerry: "You confuse me, Voltaire. If I tell you too much, I have to shoot you. I'm a very talkative person, you follow me? I get lonely up here, it is my disposition always to be lonely. I like a guy, I talk to him, then I regret myself. I remember my business commitments, follow me?"
* ''Literature/PaladinOfShadows'': Used as a joke by Mike, when asked by a beer distribution company representative how Mike had earned the money he was fronting for the Mountain Tiger Beer brewery.
* In ''[[Literature/RiversOfLondon Foxglove Summer]]'', Peter tells another police officer who asks him the truth about the supernatural "I could tell you, but then you'd have to section me".
* In ''Literature/InstrumentOfGod'' the author breaks the fourth wall to tell a story about his relationship with the intelligence community in an indirect way, then actually uses this phrase to explain why he can't be more direct.

[[folder:Live-Action TV]]
* ''Series/StarTrekDeepSpaceNine'': A scene between Weyoun, Damar, and Damar's lady friend, in the war room.
-->'''Weyoun:''' I have news.\\
'''Damar:''' Well?\\
'''Weyoun:''' Your ''friend'' doesn't want to hear this.\\
'''Damar:''' And why doesn't my friend want to hear this?\\
'''Weyoun:''' Because if she did I would be forced to have her executed.\\
''[Damar's lady friend calmly walks out]''\\
'''Weyoun:''' ''[somewhat snarkily]'' What a pleasant woman.
* ''Series/TheWestWing'': Season 7- Ep. 10 ''Running Mates'' (00:23:42 on the time bar), communications officer Will Bailey applauds deputy national security advisor Kate Harper for ''not'' using the line. (He also mentions how alluring he finds the fact that she actually ''could'' kill him with her bare hands...)
* ''Series/CrossingJordan'' episode "Out of Sight"
-->'''Dr. Nigel Townsend:''' Counterintelligence for the Royal Navy. I'd tell you more, but then I'd have to kill you.
* ''Series/{{Newsradio}}'' episode "Rose Bowl"
-->'''Joe Garrelli:''' There is a secret word that, when uttered, forces the judge to rule in your favor, then go to a secret location to paddle themselves in a secret ceremony.\\
'''Dave Nelson:''' What is it?\\
'''Joe Garrelli:''' I'd tell you, but then I'd have to kill you.\\
'''Dave Nelson:''' All right, but it better be good.
* ''Series/{{Psych}}'' episode "Poker? I Barely Know Her"
-->'''Shawn Spencer:''' Or perhaps you're referring to my license to kill. Revoked -- problems at the Kazakhstan border. I'd give you the details, but then I'd have to kill you, which I can't do because my license to kill was revoked.
* ''Series/StargateSG1'' uses a variant where an offhand comment is made about O'Neill's time of service and the possibility of writing a book about it. Due to much of his duty even before joining the SGC consisted of top secret operations, he jokes that he'd have to kill anyone who read it.
* ''Series/TheColbertReport'' is going to the Persian Gulf, but exactly when or where it will be has been sworn to secrecy by the Pentagon.
-->'''Creator/StephenColbert:''' I could tell you, but then they'd have to kill me.
* In the premiere episode of ''Series/BandOfBrothers'', Nixon already knows where the unit is going, and teases Winters with this phrase. Nixon clearly wants to share the information, but Winters refuses to ask, so Nixon just tells him anyway.
* ''Series/{{QI}}'':
-->'''Alan:''' What happened to [[{{MI6}} MIs 1, 2, 3 and 4]]?\\
'''Stephen Fry:''' Well it's very interesting, I could tell you, but then I'd have to [[SubvertedTrope eat myself]].
* One ''Series/{{Alias}}'' promotional video spoofs this with Creator/JenniferGarner addressing the audience.
--> '''Jenny:''' If we told you more about the show, we'd have to kill you.
* In the "Implosion" episode of ''Series/{{Warehouse 13}}'':
-->'''Secret Service Agent:''' Who's Mrs. Frederick?\\
'''Artie:''' I'd tell you, but then he'd have to kill you ''[pointing at Mrs. Frederick's bodyguard, who has come to pick Artie up]''
* In ''Series/TheSentinel'', when Jim and Blair go on a classified mission, Blair goes into a discussion about how police departments indoctrinate their members like a cult--Jim jokingly agrees, and says that, now that he's told Blair about it, he "''will'' be required to kill you."
* In ''Series/{{Merlin|2008}}'', Merlin tries to [[LampshadeHanging lampshade]] this by saying "Right, 'cause if you do you'll have to kill me I suppose," but Arthur responds with "Immediately and without hesitation."
* On ''Series/{{Caprica}}'', a character uses a Tauron phrase that is subtitled as "If I revealed the details, I'd have to return you to the soil."
* On ''Series/{{NCIS}}'', when Kate finds out that Tony knows her new boyfriend:
-->'''Kate:''' Steve Adler is your fraternity brother?\\
'''Tony:''' I'd show you the secret handshake, but then I'd have to kill you.
* Played with in one episode of ''Series/{{CSINY}}''. During the ColdOpen Adam is talking to a girl via webcam, using some fictional form of ChatRoulette. He asks her something - can't remember quite what - and she responds with this phrase...at which point [[spoiler: the murderer sneaks up behind her and kills ''her'' right in front of Adam, kicking off the MysteryOfTheWeek.]]
* In ''[[Series/{{Jake20}} Jake 2.0]]'', Jake's younger brother steals Jake's wallet and goes to a bar. A girl notices the [=NSA=] ID, so the brother starts pretending to be a spy. He starts saying this phrase, and she finishes it off, annoyed at the cliche. He corrects her that he'd have to sleep with her, "but if that's your thing..."
* ''Series/BuffyTheVampireSlayer:'' from the episode "Inca Mummy Girl":
-->'''Xander:''' ''[on why the life-sucking mummy won't tell him why she's crying]'' Hey, I know why you can't tell me. It's a secret, right? And if you told me, you'd have to kill me.\\
''[Ampata cries louder]''\\
'''Xander:''' Oh! That was a bad joke, and the delivery was off, too. I'm sorry.
* ''Series/{{Spaced}}'' goes for the "modern comedy subversion" option:
-->'''Daisy:''' Actually, what is your job, Mike?\\
'''Mike:''' ''[sincerely]'' If I told you that I'd have to kill you.\\
'''Daisy:''' What, is is a secret?\\
'''Mike:''' No.
* In one episode of ''Series/{{Numb3rs}}'', Amita is asking Charlie a question about exactly where he learned code phrases (beyond that it was at the NSA) and he replies with the trope. She thinks he's kidding, but he's actually quite serious.
* In ''Series/AmericasGotTalent'', after the amazing [[http://www.youtube.com/watch?v=JhqH5kxNIXM presentation]] by quick change artists David and Dania, Creator/BrandyNorwood asks David "How do you do that?", to which an exhausted David replies: "We could tell you, and then we'd have to make you disappear."
* In ''Series/{{Gotham}}'', when Nygma asks Hugo Strange who really runs Indian Hill and Wayne Enterprises, the PsychoPsychologist replies "I could tell you, but then I'd have to lobotomise you."
* ''Series/LukeCage2016'': Mariah complains to Diamondback about how she got lost trying to find on her own the warehouse where he stores his cache of Hammer weaponry for street dealing:
-->'''Mariah Dillard:''' You could at least let Tony bring me. I got lost three times trying to find this damn place.
-->'''Willis "Diamondback" Stryker:''' Sure, but then I would've had to put a bullet in the back of his head. No one comes here. Period.

* MF DOOM in the song "Superfriends": "I don't think you wanna know, even if you still do, and want me to, I'll tell you, but then I'll have to kill you."
* Music/WeirdAlYankovic's ode to EspionageTropes, "Party in the CIA": "Burn that microfilm, buddy, will you, / I'd tell you why but then I'd have to kill you."

* The Storyteller in Series 5 Episode 2 of ''Radio/JohnFinnemoresSouvenirProgramme'':
-->Well, since you ask me for a tale of espionage, treason and people in suits looking out of windows with rain running down them. ([[AmbiguousSyntax The windows I mean, not the suits]]), it so happens that I could tell you such a story, but then I would have to kill you! Hahahaha! Oh, no, wait. This is a story about how I used to be a spy, so I ''could'' tell you, but then I [[SincerityMode would have to kill you]]. It's all right, though; I was going to kill you anyway.

[[folder:Tabletop Games]]
* ''TabletopGame/{{Paranoia}}'': one suggested variant on "That information is outside your security clearance" is...well, this trope.

[[folder:Video Games]]
* In the second ''VideoGame/GabrielKnight'' AdventureGame, during the hunting club reunion, if Gabriel asks [[HairTriggerTemper Von Zell]] what he is talking about with Klingmann, Von Zell replies "We could tell you, Herr Knight, but then we'd have to kill you."
* ''VideoGame/BanjoKazooie: Nuts and Bolts'': If you pay Bottles the Mole 6,000 musical notes (the highest price for any single item in the game) to tell you the "truth" about the infamous Stop 'n' Swop, he responds with "I could tell you, but then I'd have to kill you, and we can't show that in a game with this rating. Thanks for the notes!"
* Blair, in ''Videogame/WingCommander IV'' when he comes aboard the TCS ''Lexington'', uses this line to poke fun at Maniac.
* In ''VideoGame/TheElderScrollsVSkyrim'', when the player character joins the Dark Brotherhood and gains access to their sanctuary, many members are often conversing on their latest assassination contracts. One particular line of dialogue is Nazir saying, "It's all thanks to a special technique I developed. I call it the 'Razor-Winged Butterfly.' I'd teach it to you... but then I'd have to kill you."
* Used as a StopPokingMe line by the Druid of the Talon in ''VideoGame/WarcraftIII''.

[[folder:Web Comics]]
* Seen in ''Webcomic/SweetBroAndHellaJeff'':
-->[[http://www.mspaintadventures.com/sweetbroandhellajeff/?cid=009.jpg GOD. DAAAAAAMMNN]].
* The page image is from an ''Webcomic/{{xkcd}}'' strip where one character asks another what he's up to and receives the reply [[http://xkcd.com/707/ "If I told you, I'd have to kill you. I mean, sooner."]]
* ''Webcomic/GirlGenius'':
** Combined this with "TheEasyWayOrTheHardWay" [[http://www.girlgeniusonline.com/comic.php?date=20070115 here,]] when Master Payne gives two Wulfenbach troopers the choice of his being a good magician (who doesn't reveal how a trick is done) or an evil one (who doesn't leave any evidence there was a trick in the first place).
** In [[http://www.girlgeniusonline.com/comic.php?date=20130201 this strip]] Der Kestle declines to reveal information about [[spoiler:Airman Higgs]] to Zeetha, as doing so would require Zeetha to be killed.
** Inverted when Agatha [[http://www.girlgeniusonline.com/comic.php?date=20160523#.V0Lvur6wjow asks]] how the Smoke Knights do their StealthHiBye stuff:
--->'''Smoke Knight:''' If we told you, we'd have to let you live.\\
'''Agatha:''' What?\\
'''Smoke Knight:''' For a very, very long time.\\
'''Agatha:''' Er, right.
%%* [[http://www.bugcomic.com/comics/seduced-by-mister-e/ Mocked]] by ''Webcomic/{{Bug|Martini}}''.
* In one ''Webcomic/ElGoonishShive'' strip Justin [[http://www.egscomics.com/?date=2010-11-29 worries]] that Mr Verres may have to kill him over things he's ''already'' told him.
* Happened in ''Webcomic/SchlockMercenary'' in a briefing between general Xinchub, some UNS Govt guy dealing with the same secret projects that ran into each others, and a major not cleared for one of them, who [[http://www.schlockmercenary.com/2003-02-09 was stupid enough to ask a clarifying question]] which [[HeKnowsTooMuch made the issue moot]].
* From ''Webcomic/TheLastDaysOfFoxhound'':
-->'''Naomi:''' It's not that I have a problem with it. But why do they want that?\\
'''Ocelot:''' Welcome to Ocelot Shack. You've got questions, [[ImpliedDeathThreat we've got bullets]].
* Played with in a strip from ''[[http://www.creativeuncut.com/comic-itgs.html Inside The Gamer's Studio]]''. Whit, the host, is interviewing [[VideoGame/FinalFantasyVII Vincent Valentine]] about his role in ''[[Anime/FinalFantasyVIIAdventChildren Advent Children]]'' film. Vincent quotes the trope, but Whit says he can live with it. Vincent whispers something in his ear and immediately shoots him dead. A "Retry" screen appears, and [[HereWeGoAgain Whit starts again from when he asked the question.]]
* Combined with TheFourthWallWillNotProtectYou in ''Webcomic/SkinHorse'', Shaenon and Jeff [[http://skin-horse.com/comic/said-the-man-in/ warn the readers]] that if they reported what Tip and Ginny were ''actually'' talking about, they'd have to kill us. Through the screen.

[[folder:Web Original]]
* ''WebVideo/BumReviews'': Chester A. Bum admits that he's Super-Bum. He then says that since he's told you, he'll have to kill you. Good news is he's just joking -- he actually makes the viewer impotent.

[[folder:Western Animation]]
* Referenced in ''WesternAnimation/KimPossible''. A soldier working on a top secret project blurts out "Neutronalizer" during Wade's briefing. Mr. Dr. Possible asks "This isn't one of those, 'I'd tell you but then I'd have to kill you' sort of things, is it?" The soldier pauses awkwardly and tells everyone to just forget what they heard.
* ''WesternAnimation/TheGrimAdventuresOfBillyAndMandy'':
** In "Big Boogey Adventure", the movie, Billy asks his future self what he is going to have for lunch on Thursday. His future self replies with the trope name.
** In an earlier episode, Billy asks why [[EvilCounterpart Bobby]] wants his life, to which Bobby replies, "If I told you, then I'd have to [[NeverSayDie destroy]] you." A confused Billy then asks, "[[DumbassHasAPoint Aren't you going to]] [[KillAndReplace destroy me anyway?]]"
* In the first episode of ''WesternAnimation/GodzillaTheSeries'', Nick says this word for word when Major Hicks asks who hacked right into [[http://en.wikipedia.org/wiki/Consolidated_Edison Con Ed]]'s satellites, which was the resident PlayfulHacker, Randy.
* In ''WesternAnimation/StevenUniverse'', Amethyst jokingly said this to young Greg Universe when he asks of Rose's whereabouts.

[[folder:Real Life]]
* Averted by the NSA. Because NSA employees are barred from saying anything about the nature of their work (no matter how mundane), it became vogue, at one point, for them to say this line when friends and family asked. The brass had to put a stop to it because it was overly dramatic and only made people more intrigued.
->''You now know too much about this trope. *BANG*''