[[quoteright:300:http://static.tvtropes.org/pmwiki/pub/images/Jekyll_and_Hyde_6799.jpg]]

->''"If each, I told myself, could be housed in separate identities, life would be relieved of all that was unbearable..."''
-->-- '''Henry Jekyll'''

Source of the JekyllAndHyde trope, this 1886 book by Creator/RobertLouisStevenson has been much filmed, but practically all the films turn the plot inside out. Note that the original title was ''Strange Case of Dr Jekyll and Mr Hyde'', omitting the "The" for some reason.

The book begins with a mystery. When a girl is brutally attacked late one night, her attacker, calling himself Mr Edward Hyde, buys off the witnesses with a cheque for a small fortune, signed by the eminently respectable Doctor Henry Jekyll.

Jekyll's friend and legal advisor, Gabriel John Utterson, is disturbed when he learns this, since Jekyll has recently made Hyde his heir. While Utterson investigates this, Hyde is witnessed committing a savage murder of a prominent Member of Parliament. Jekyll claims there is nothing to worry about, but Utterson becomes convinced his friend is being blackmailed.

Before Utterson can do anything, Jekyll's butler Poole contacts Utterson to report that a stranger has locked himself in the lab. When they break into the room they find Hyde, having committed suicide by poison, and two letters explaining everything.

Jekyll had been trying to invent a [[AppliedPhlebotinum potion]] which could separate his good and evil sides. When [[ProfessorGuineaPig Jekyll tested it]], he was now transformed into 'Mr Hyde', a manifestation of his evil side with no trace of morality, but his normal personality remained unchanged. In other words, as Dr. Jekyll he was a man with mostly good and ''some'' evil urges, as Mr Hyde he was a man with only evil urges. After some cautious experimenting, Jekyll decided he ''liked'' this side-effect. As Mr Hyde, he could indulge himself in every pleasurable vice, and never be suspected as Hyde looked completely different. However, Hyde eventually committed murder, Jekyll resolved [[TemptingFate never to use the potion again]].

But after a few months, Jekyll began spontaneously changing into Hyde. Only by drinking the potion could he retain his own form, and the potion was running out -- not to mention that ever since the murder, the police had been searching relentlessly for Edward Hyde. When Jekyll made a new batch of the potion, it didn't work; his original chemical samples had been contaminated, and it was the impurities that had made the transformation possible. At the end of his letter, Jekyll writes that he soon will change into Hyde, and thus his life will end.

There have been several adaptations and parodies of this book, including:
* A highly successful stage play that opened in America not long after the book came out and toured for 20 years. It was this play that introduced the idea of the two [[LoveInterest love interests]]--Jekyll's good girl fiancee and Hyde's slutty barmaid/prostitute girlfriend. This plot thread, not part of the original story, [[RetCanon occurs in almost all later adaptations]].
* Straightforward adaptations in 1919 (with John Barrymore), 1931 (with Fredric March and Miriam Hopkins), 1941 (with Creator/SpencerTracy, Creator/IngridBergman and Lana Turner) and 1960 (a Hammer version with Paul Massie). All these adaptations made substantial changes to the main plot - in particular, Jekyll tends to be cast much younger than he is in the novel, and a female love interest is usually added. They also abandon the character of Utterson and his investigation for a story centered on Jekyll and Hyde. Also, the March version is the only one to regularly use the (little-known) correct pronunciation of "Jekyll" (''Jee''-kyll). The 1931 film is probably the best-regarded film version. It offers a rare case of a horror film winning an AcademyAward, as March won Best Actor for his portrayal of Jekyll and Hyde.
* ''The Janus Head'', a 1920 silent German film version directed by F.W. Murnau and starring Conrad Veidt. It changes the characters' names to Dr. Warren and Mr. O'Connor. Also has a very young Bela Lugosi as the butler. It is also apparently lost forever, but if the production notes are to be believed, it has the first moving camera in cinema history.
* Stephen Weeks's version, ''I, Monster'' (produced by Creator/AmicusProductions) keeps to the original plot but changes the names of Jekyll and Hyde in an attempt to keep the twist.
* ''TheNuttyProfessor'' (both JerryLewis' and EddieMurphy's versions) are comedic takes on the concept, where a nerdy scientist changes into a cool guy.
* The TV sitcom ''FamilyMatters'' has geeky Steve Urkel develope a potion that turns him into the suave, handsome Stephan Urquelle.
* ''The Two Faces of Doctor Jekyll'' puts an interesting twist on the Jekyll/Hyde dichotomy: Jekyll is hirsute, sloppy dressed, mannerless and abrasive, while Hyde is elegant, suave, charming and debonair.
* ''Dr. Heckyl and Mr. Hype,'' a 1980 comedy/horror with OliverReed, followed the ''Nutty Professor'' formula: the kindy Heckyl is horribly ugly while his violent alter-ego is good-looking.
* The 1971 HammerHorror ''Dr. Jekyll and Sister Hyde'' and the 1995 comedy ''Dr. Jekyll and Ms. Hyde'' both add a GenderBender twist to the story.
* ''Mary Reilly'' tells the story with a romance/horror twist: Hyde was Jekyll's attempt to become young and strong again.
* Frank Wildhorn and Leslie Bricusse adapted it during the '90s into a stage musical, ''Theatre/JekyllAndHyde''.
* ''{{Jekyll}}'', a 2006 modern day TV miniseries involving a descendant of the pair, written by Creator/StevenMoffat. Also notable for an example of using the 'Jee-kyll' pronunciation.
* In ''Comicbook/TheLeagueOfExtraordinaryGentlemen'' and its [[Film/TheLeagueOfExtraordinaryGentlemen film adaptation]], Jekyll and Hyde are made into {{Exp|y}}ies of Bruce Banner and the Comicbook/IncredibleHulk, who were in turn based off Jekyll and Hyde. The pair can communicate - Jekyll sees Hyde in mirrors, and omnipresent in his subconscious. Hyde's powers of perception are not usable by Jekyll except if the former advises the latter. The comic depicts Hyde as a huge, monstrously strong humanoid, which Hyde himself explains - separated into distinct individuals, Jekyll grows weak and frail without Hyde's passion, while Hyde grows in power without Jekyll's morals to limit him.
* ''Film/VanHelsing'' had Hyde as the first monster the titular Van Helsing fights. Hyde is an ape-like monster who battles Van Helsing in the BatmanColdOpen. Hyde turns back into Jekyll on his death, unlike the original story.
* An animated prequel of ''Film/VanHelsing'' fleshes out the story. Apparently the doctor has the hots for Queen Victoria of England. And he harvests essence from young women to make a temporary youth potion for the queen.
* A direct-to-video version starring [[Film/{{Candyman}} To]][[Film/StarTrekVTheFinalFrontier ny To]][[FinalDestination dd]] in 2009. Unlike most adaptations, it tried to remain close to the novel by giving the impression that Jekyll & Hyde were two different people. At least until about two-thirds of the way into the movie.
* An infamous NintendoEntertainmentSystem game by {{Toho}}, which routinely shows up on lists of the worst NES games of all time due to ugly graphics and sadistic FakeDifficulty.
* There's a 70s Blaxploitation flick, ''Dr Black and Mr Hyde'', which cashed in on the Blaxploitation horror craze that was started by ''Blacula''.
* A 1980s Australian kids' cartoon attempted to stick to the original novel the most.

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!!This book provides examples of:

* AllThereIsToKnowAboutTheCryingGame: The work is [[MainstreamObscurity well-known by name]], but all that most people have heard about it is [[JekyllAndHyde the twist ending]]. Many do not even know that the dual identity story was originally a twist at all, and most newer adaptations treat it as a foregone conclusion. Some even make Hyde himself some sort of ugly were-monster rather than just a really evil man, most notably in the infamous NES game released by Bandai.
* AlternateIdentityAmnesia: Neither Jekyll nor Hyde have very clear memories of what the other does.
* ApocalypticLog: TheReveal comes in ''two'' of these, one left by Dr. Lanyon, giving an account of how Jekyll revealed his secret to him, and the second a confession by Jekyll himself, written after he could no longer make the formula and realized Hyde would take over completely. Both are read by Utterson starting at around the 3/4 mark.
* AppliedPhlebotinum: The means by which Hyde is created. This was a time when chemistry and and especially the workings of the human mind were still relatively unknown (even more so then today, that is), and therefore could be used in the same way radiation was used as a reason for giant monsters and superpowers in the 1950's.
* AmateurSleuth: This is basically Utterson's role in the original story.
* BastardBastard: Hyde is not only smaller but younger-looking than Jekyll, and Utterson briefly wonders if he's the by-blow of Jekyll's youthful indiscretions (though the story phrases it far less bluntly):
-->"Poor Harry Jekyll," he thought, "my mind misgives me; he is in deep waters! He was wild when he was young; a long while ago to be sure; but in the law of God, there is no statute of limitations. Ay, it must be that; the ghost of some old sin, the cancer of some concealed disgrace: punishment coming, ''pede claudo'', years after memory has forgotten and self-love condoned the fault."
* BitterAlmonds: "The strong smell of kernels that hung in the air"--that is, almond kernels. Hyde has taken cyanide.
* BodyHorror: Though not pushed as far as later writers went with it.
* TheCaseOf: One of the earliest works to use this intriguing title template.
* ADarkerMe: This is the appeal of Hyde for Jekyll; he even refers to Hyde as "the darker side of my nature".
--> '''Jekyll''': This, too, was myself. It seemed natural and human.
* DeadManWriting: Jekyll wrote a complete briefing about what happened to him (it's the last chapter of the book), but it mustn't be opened before his [[SplitPersonalityTakeover disappearance]] or death.
* DevilInPlainSight: Everyone can sense that there is something wrong with Hyde, mostly because he is pure evil. They think he might be deformed in some way, but nobody can quite put their finger on how.
* DoesThisRemindYouOfAnything:
** The book is a thinly veiled metaphor for drug addiction. Stevenson was an opium user.
** The small girl running down the street who is knocked over by Hyde? Out in the small hours in the morning, alone in central London? The explanation that she was fetching a doctor rings hollow with some critics: the government acts of the 1870s that covered homosexuality also, less famously, first made sex with 12-15-year olds illegal- child prostitution was another worry at the time.
** The description of Sir Danvers' beauty- thought by some to make him sound rather camp- also gets read like this.
* DrivenToSuicide: After Jekyll realizes that Hyde will take all control of him - both of his body and his personality - he restrains himself to his lab until the final transformation. Hyde takes cyanide when Utterson shows up outside the lab and demands to see Jekyll.
* EvilFeelsGood: Only the original version, not the adaptations. This is the very reason Jekyll thinks separating his evil side from his good side is a good idea -- as Hyde, he's free to do anything without restraint from the law -- or, far more importantly, his own conscience. This was a very prescient idea in Victorian England.
* EvilIsNotAToy: Releasing Hyde -- Easy. Getting rid of him -- Not so much.
* {{GIFT}}: The great appeal of Hyde to Jekyll is that he can't be held responsible for Hyde's crimes.
--> '''Jekyll''': But for me, in my impenetrable mantle, the safely was complete. Think of it--I did not even exist! Let me but escape into my laboratory door, give me but a second or two to mix and swallow the draught...and whatever he had done, Edward Hyde would pass away like the stain of breath upon a mirror; and there in his stead, quietly at home...would be Henry Jekyll.
* GoMadFromTheRevelation: Dr. Lanyon after he sees Hyde transform into Jekyll for the first time.
* GoneHorriblyRight: The potion that separates good and evil seemed like a good idea, but Jekyll forgot [[SplitPersonalityTakeover that one little possible side-effect]]...
* HairTriggerTemper: Some minor annoyance in conversation with Danvers Carew causes Hyde to fly into a rage and beat him to death.
* HaveAGayOldTime:
** Here is how Mr. Enfield explains his reluctance to start asking questions about other people's business:
--> "...the more it looks like Queer Street, the less I ask."
** Then there's how Jekyll describes the duality of man, using an old word for a bundle of sticks:
--> "It was the curse of mankind that these incongruous faggots were thus bound together...."
* HearingVoices: It is highly suggested in the final chapter that Jekyll was able to hear Hyde inside his head, because "(Hyde) was constantly demanding to get out". However, there is no sentence that 100% confirms this.
* {{Hypocrite}}: Jekyll does not take responsibility for the evil actions of Hyde, yet he takes the potion specifically to enjoy performing evil actions as Hyde. Stevenson called this Jekyll's FatalFlaw in a letter to a friend.
* InvoluntaryShapeshifter: After months of taking the potion, Jekyll finds that he is turning into Hyde without it.
* IncrediblyLamePun
--> '''Utterson:''' If he be Mr. Hyde, I shall be Mr. Seek
* JekyllAndHyde: The {{Trope Namer|s}} -- oh, and this is now a byword of someone who is nice one minute, nasty the next.
* MiraculousMalfunction: An "impurity of salt" is what makes the transformation from Dr. Jekyll into Mr. Hyde possible. This is what finally dooms Jekyll--he doesn't know what the impurity is, and when his salt runs out, he can't replace it.
* MyGodWhatHaveIDone: Jekyll after Hyde kills Danvers Carew.
* TheNapoleon: Hyde is frequently described as being "short," "small" and even "dwarfish," in contrast to the taller Jekyll. This is explained as being because Jekyll never indulged in his evilness before, so his evil side is "underdeveloped." Hyde is, however, very dangerous.
* NeverMyFault: Even when writing his final letter, Jekyll still insists that, even now, he doesn't consider Hyde's actions ''his'' actions. ([[{{Hypocrite}} His choice of pronouns says otherwise]].)
* NoPlansNoPrototypeNoBackup: This is an accident on Jekyll's part, as it turns out to be an unknown impurity that makes the stuff work.
* NoPronunciationGuide: It should be "''Jee''-kyll", not "''Jeh''-kyll". Not that ''that's'' ever stopped anybody from pronouncing it "''Jeh''-kyll" for decades.
* NoodleIncident: Stevenson never goes into great detail about most of the things that Hyde does on his nightly escapades before crossing the MoralEventHorizon by murdering Sir Danvers Carew for no reason; the narrative only states that his activities were of an evil and lustful nature. Given the Victorian England setting and what was considered abhorrent for the time, he may have been engaging with prostitutes and drinking heavily in shady taverns, but we can only surmise.
* ObviouslyEvil: Hyde's appearance is banal, yet everyone who looks at him instinctively recognizes his evil.
* ProfessorGuineaPig: The UrExample, beating out ''Literature/TheInvisibleMan'' by a decade.
* PsychoSerum: TropeMaker
* PureIsNotGood: Henry Jekyll, a man with mostly good and some evil urges, thinks that if he could separate his good and bad urges into separate identities, life would be better, because he would be free of morality and can indulge himself on every pleasurable vice without hypocrisy. Then his bad side crosses the MoralEventHorizon and Jekyll’s life is threatened. ''The only thing that made Jekyll’s safe was his hypocrisy''. Mirrored with the “impurity of salt”, the impurities had made the potion work. ''Without the contamination of the samples, he cannot make the transformation work''.
* SexIsEvilAndIAmHorny: It is implied that among the aforementioned vices was womanizing. In his confession, the doctor characterizes "a certain impatient gaiety of disposition" as the worst of his vices. At the time, "gay" was used to describe a ''heterosexual'' person who was inordinately lustful.
* ShadowArchetype
* TheSmurfettePrinciple: One of critics' favorite subjects is how no nominal women appear in the original book or even get involved in the plot except as spectators or victims.
* SplitPersonalityTakeover: Likely the UrExample.
* TechnicolorScience: The potion starts out red and then turns purple before settling on green.
* ThisIsYourBrainOnEvil: The addiction metaphors are obvious... and appropriately creepy. This was written at a time when the effects of opium addiction were just coming to light.
* TwistEnding: The "[[ItWasHisSled twist]]" comes at about the 3/4 mark, and then closes out with Jekyll's own posthumous explanation for everything that happened.
* UnstoppableRage: After Hyde goes into a rage and attacks Carew, he exults in the thrill of the evil action and beats the man to death.
* WouldHurtAChild: In his first appearance Hyde literally walks over a little girl he meets on the street.
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!!Tropes common to multiple adaptations:
* AdaptedOut / DemotedToExtra: The fate of Mr. Utterson, due to most every adaptation centering on Jekyll from the start rather that Utterson investigating a mystery, as the novel did. In the 1920 film he pops up towards the end as one of Jekyll's friends, in the 1931 film he is an extra, and in the 1941 film he's completely omitted.
* AdaptationalBadass: The part about Hyde being a diminutive man, much smaller than Jekyll, is usually adapted out. Instead, Hyde is usually portrayed as a burly brute of a man, larger than Jekyll.
* ArtifactTitle: A good number of adaptations preserve the "Strange Case" portion of the original title. Although to the modern audience, it's not much of a mystery anymore since adaptations, unlike the original story, typically show the story from Jekyll's point of view.
* BettyAndVeronica: Jekyll almost always has an innocent girlfriend/fiancee while Hyde almost always has an earthier, more sexually available woman that he brutalizes. As noted above, this was not present in the novel.
* PragmaticAdaptation: Jekyll wasn't the central character of the original story--the story is told from the POV of Mr. Utterson, Jekyll's old friend and lawyer who investigates the mystery. Most of the original story depicts Hyde's actions as being told about instead of shown. The twist ending was revealed in a letter where everything is again told instead of shown. Most adaptations, instead, focus on depicting Jekyll's dramatic struggle between his two selves and his eventual downfall, since everybody already knew the ending. (Utterson, the main character, is a bit part in the 1931 film and is left out of the 1941 film completely.)

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!!The 1920 movie provides examples of:
* ChekhovsGun: Gina, the Italian dancer that is the Veronica in this version's BettyAndVeronica pair, has an old ring that has a secret capsule for storing poison (this actually being an old myth about Lucrezia Borgia). Hyde takes it from her. At the end, Jekyll swallows the poison to stop Hyde from raping Millicent.
* TheFilmOfTheBook: While still using the BettyAndVeronica trope and not being a mystery, this film is somewhat more faithful to the novel than the 1931 and 1941 adaptations. Utterson appears in this version, although his importance is reduced, and Jekyll poisons himself rather than being shot as in 1931 and 1941.
* OpiumDen: Hyde visits one, although he doesn't take any opium.
* PinkElephants: An opium addict in withdrawal starts hallucinating red ants.
* ShoutOut: Sir George Carew's quote, "The only way to get rid of a temptation is to yield to it", is a direct lift from Creator/OscarWilde and ''Literature/ThePictureOfDorianGray''.

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!!The 1931 movie provides examples of:
* EpicTrackingShot: The movie begins with a three-minute continuous shot which moves between two interiors across a large set -- both technically and aesthetically daring for the time. Even more impressively, this shot is from Jekyll's point of view. After a cut while Jekyll is riding in a carriage, a second Epic Tracking Shot follows Jekyll through the streets, out of his cab, and into a lecture hall.
* EvilFeelsGood: It's clear that Jekyll uses Hyde to indulge his frustrated sexual desires. He finally makes the decision to let Hyde loose after Miriam's domineering father demands they wait eight months to be married (until the anniversary of his marriage to Miriam's mother).
* {{Fanservice}}: This film predates UsefulNotes/TheHaysCode, and has some racy for its day moments (mostly with Ivy). In the scene where she tries to seduce Jekyll, Miriam Hopkins wears less clothing than any actress would have been allowed to get away with just a few years later. Her frank offer of sexual service in return for protection from Hyde also marks this as a pre-Code film. According to TheOtherWiki, when this film was re-released in 1936, eight minutes had to be cut to meet the stricter censorship standards.
* HaveAGayOldTime: Miriam (Dr Jekyll's fiance) says that she does not believe Dr Jekyll loves her seriously. He responds with "Oh, I love you better than that. I love you gayly!"
* IdiosyncraticWipes: This film uses what might be described as diagonal wipes, where a wipe starts on either the left-hand side and pivots in a clockwise motion across the scene, or a wipe starts on the bottom of the frame and pivots in a counter-clockwise direction. Just to make it more idiosyncratic, the wipe usually stops in the middle for a little bit, resulting in a diagonal SplitScreen where action is going on in both corners, before restarting and finishing the transition to the new scene.
* LectureAsExposition: Jekyll gives a long lecture to a group of medical students which explains his theory behind the dual nature of man.
* MadScientistLaboratory: Jekyll's is a perfect example, with lots of big beakers, test tubes, distilling columns, and flasks of smoking liquid that would probably be TechnicolorScience if the film hadn't been shot in black and white.
* MatchCut: Several Match Cuts, quite sophisticated for 1931, are used to demonstrate Jekyll's transformation into Hyde.
* NotEvenBotheringWithTheAccent: This didn't stop March from winning an Oscar.
* POVCam: Used several times from Jekyll's point of view, including the two [[EpicTrackingShot Epic Tracking Shots]] that open the film, as well as the scene where Jekyll downs the potion for the first time. Twice--in the opening scene and when Jekyll downs the potion--the film includes a shot of Jekyll-as-camera looking at a mirror. This was done by putting March on the other side of a mirror that was actually just a hole in the wall, with a reversed portion of the set behind him.
* RedemptionInTheRain: Inverted as thoroughly as a trope can be inverted, unless one can be redeemed into evil. When Hyde leaves the laboratory for the first time, it's pouring rain. Hyde spreads his arms and turns his face to the rain in obvious joy.
* VisualInnuendo: As Jekyll's obvious sexual frustration reaches its peak after receiving a letter from Miriam stating she'll be gone for a month, a kettle in his fireplace boils over.
* WhipPan: Used during the first transformation sequence, as the world spins around Jekyll.
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!!The 1941 movie provides examples of:
* GettingCrapPastTheRadar: A pretty startling example for 1941. During another transformation montage, we see Jekyll as a carriage driver whipping his horses. Then the horses transform into Creator/IngridBergman and Lana Turner, and Jekyll continues to whip them.
* NotEvenBotheringWithTheAccent: Tracy, like March before him, doesn't even try for any kind of British accent.
* VisualInnuendo: During one of the hallucinatory montages when Jekyll transforms into Hyde, he has a vision of Ivy the barmaid's head as the cork in a champagne bottle--and the cork pops.

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