Stevenson drew on several real and intellectual sources for this novella. The most direct inspiration was Deacon William Brodie, an eighteenth-century Edinburgh craftsman who was respected by day but led a secret criminal life at night. Stevenson grew up in Edinburgh and was fascinated by Brodie's double life. Charles Darwin's theory of evolution, which suggested that humans still carry animal instincts beneath their civilised surface, also influenced the portrait of Hyde as a creature of primitive impulses. Calvinist religious ideas, which Stevenson encountered in his Scottish upbringing, reinforced the belief that human nature is divided between good and evil.

Stevenson reportedly had a dream about a man who drank a potion and transformed. When his wife woke him, he was upset at being disturbed from what he called a fine story. He wrote the first draft in approximately three to six days, which his wife Fanny then encouraged him to expand into a fuller allegorical tale.

The full title, "The Strange Case of Dr. Jekyll and Mr. Hyde", performs two important functions. The phrase "Strange Case" uses the language of legal or medical reports, immediately suggesting that an investigation will take place. The word "Strange" signals mystery, while "Case" implies a puzzle to be solved: readers are positioned as investigators from the first line. The adjective "Strange" also invites readers to consider all three possibilities, that the case may be medical, legal, or criminal.

"Dr. Jekyll" is the name of the respectable protagonist, Henry Jekyll, a well-known physician. The surname Jekyll is derived from the Breton name Judicael and traditionally means generous lord. "Mr. Hyde" is the other name in the title. "Hyde" comes from the Old English word meaning to hide or conceal, signalling that this personality is kept secret. Together, the two names announce the novella's central theme: the conflict between the public self and the hidden self.

The novella was first published in January 1886 by Longmans, Green and Co. in London. It was sold as a "shilling shocker", a cheap booklet intended for a wide popular audience. This format, though inexpensive, was a respectable way to reach large numbers of readers quickly. Stevenson is said to have written the first draft in just three to six days after being inspired by a dream about transformation. His wife Fanny encouraged several revisions, including a stronger focus on the allegorical meaning of the story.

The novella was an immediate commercial success, selling approximately 40,000 copies in the first six months in Britain alone. Within a year it had been translated into several languages. It became one of the most widely adapted literary works of the Victorian period and has since been translated into over 60 languages. It remains a key text in the study of Victorian literature and popular culture.

The novella combines two genres: the Gothic novel and the classic detective story. Gothic elements are visible throughout: the dark, fog-filled London streets, the sinister laboratory hidden at the back of a respectable house, the terrifying bodily transformation, and the atmosphere of concealed evil. These Gothic features also highlight the dual nature of Victorian society, in which a respectable public face often concealed darker private realities.

At the same time, the character of Mr. Utterson functions as a detective. Although he is a lawyer by profession, he questions witnesses, examines documents, follows clues, and attempts to solve the mystery of Hyde's identity. Even though Utterson does not ultimately discover the truth himself, his investigation drives the narrative and builds sustained suspense. The truth is revealed only in the final chapter, through Jekyll's own confession. The combination of Gothic horror and detective suspense makes this one of the most distinctive novellas of the Victorian period.

The novella is divided into ten chapters and concludes with two first-person confessional letters. The first eight chapters follow Mr. Utterson as he investigates the mystery from an outside perspective. His limited knowledge mirrors the reader's own uncertainty: both Utterson and the reader gradually collect clues without understanding their full meaning. This external perspective creates sustained tension throughout the first two-thirds of the novella.

The structure then shifts in the final two chapters. Chapter 9 introduces Dr. Lanyon's letter, the first first-person account, which describes a key transformation scene that Utterson cannot witness. Chapter 10 is Dr. Jekyll's full statement, the final and most complete first-person voice, which explains the entire truth. This delayed revelation is one of the most effective structural choices in Victorian fiction. Stevenson uses a frame narrative technique, in which multiple voices are combined to construct a complete picture of events that no single narrator could provide alone.

The novella follows Mr. Utterson, a London lawyer and close friend of Dr. Henry Jekyll. Utterson becomes alarmed when he learns that Jekyll has changed his will to leave everything to a mysterious man named Edward Hyde. Through a series of accounts from several narrators, including a maid, Dr. Lanyon, and Jekyll himself, the truth gradually emerges.

Jekyll has created a potion that separates the two sides of his personality. As Hyde, he acts on his darkest impulses without guilt or remorse. Hyde commits increasingly violent acts, including the murder of Sir Danvers Carew. Over time, the transformations become uncontrollable: Jekyll begins to turn into Hyde without drinking the potion. When the specific chemical salt needed to reverse the transformation runs out, Jekyll is trapped. Unable to escape Hyde, and unwilling to face trial for Hyde's crimes, he takes his own life. His final letter reveals that he and Hyde were always the same person.

The novella is set in late Victorian London. The physical settings mirror the characters' duality and the dual nature of Victorian society itself. Dr. Jekyll's town house, located in a prosperous area of London near Leicester Square, represents his public, professional identity. It is described as well maintained and comfortable, as "the pleasantest room in London". The adjoining laboratory, accessed through a separate door in an ugly side street, represents his hidden life as Hyde.

The contrast between the front and back of the same property is one of the novella's most powerful symbols. The front is elegant and respectable; the back is described as bearing "marks of prolonged and sordid negligence" and associated with "evil deeds". This physical division reflects Jekyll's inner division between his public self and his private desires. Most scenes involving Hyde take place at night or in fog, creating a Gothic atmosphere of darkness and concealment. The setting of London itself, a city of contrasts between wealth and poverty, adds to this sense of a society with two faces.

The three main characters are Dr. Henry Jekyll, Mr. Edward Hyde, and Mr. Gabriel John Utterson. Jekyll is a respected physician and scientist who believes he can separate the good and evil sides of his nature through chemistry. He is charming, generous, and socially prominent, but deeply troubled by his hidden desires. Hyde is Jekyll's animalistic alter ego: small, pale, and universally repulsive. Observers cannot explain exactly why Hyde repels them, but all feel a strong physical aversion to him. The name Hyde signals concealment and the need to hide. As Hyde, Jekyll experiences pleasures that his respectable life denies him, but with increasingly violent consequences.

Utterson is Jekyll's lawyer and closest friend. He is described as cold but never judgmental, honest, reliable, and deeply committed to justice. He represents the values of the Victorian professional class: discretion, loyalty, and a strong moral sense. He is known for keeping silent on purpose rather than saying something he might regret. As an investigator who never fully solves the case, he also represents the limits of rational inquiry when faced with irrational phenomena. Secondary characters, including Dr. Lanyon, Mr. Enfield, and the maid, each contribute partial accounts that help to build the full picture of events.

The novella uses a third-person limited narrator for most of its chapters. The primary external narrator is Mr. Utterson, whose perspective is both rational and moral. Because Utterson can only observe events from the outside, the reader shares his confusion and growing sense of dread. This technique allows Stevenson to withhold information without deceiving the reader: both narrator and reader are genuinely puzzled. Utterson's narrative is supplemented by accounts from several secondary narrators, including Mr. Enfield, the maid, and Dr. Lanyon, each of whom provides a different piece of the puzzle.

The narrative shifts to first-person in the final two chapters. In Chapter 9, Dr. Lanyon writes a confessional letter describing the transformation he witnessed. In Chapter 10, Jekyll himself writes a full statement, the only chapter in which the full truth is revealed. These two first-person voices are essential: only someone who has directly experienced the transformation can explain it. The use of multiple narrators allows readers to piece together the story gradually, just as Utterson does, and ensures that the shocking revelation at the end is both surprising and fully explained.

Stevenson uses several narrative techniques to create suspense and psychological depth. Foreshadowing appears early: in Chapter 1, the sinister door that leads to Jekyll's laboratory is described before its significance is understood, presaging the secret at the heart of the story. Cliffhangers are used at the end of several chapters to maintain momentum and encourage continued reading. Flashbacks appear in the final two chapters, when Lanyon and Jekyll describe past events in their confessional letters, filling in gaps in the narrative that Utterson could not witness.

The use of multiple narrators creates a fragmented, incomplete picture of events that the reader must reconstruct. Stevenson also uses direct dialogue, descriptions of physical environments, and Utterson's own reflections to vary the narrative pace. Contrast is used throughout: light versus dark settings, respectable appearance versus hidden reality, the front and back of Jekyll's house. These contrasts reinforce the novella's central theme of duality. The combination of Gothic atmosphere and detective structure gives the narrative its distinctive tone: rational investigation into genuinely irrational events.

The central theme is the duality of human nature: the idea that every person contains both good and evil impulses. Jekyll and Hyde represent these two sides of a single identity. Stevenson was influenced by Calvinist theology, which teaches that human beings are naturally sinful, and by Darwinian biology, which suggests that humans carry animal instincts beneath their civilised behaviour. The novella asks whether these two sides can be separated, and answers that they cannot: to deny the dark side entirely is to make it more dangerous.

A second important theme is the Victorian compromise: the social expectation that respectable people will conceal their private desires behind a public facade of virtue. Jekyll is destroyed not only by Hyde but by the hypocrisy of a society that forces him to lead a double life. His public respectability depends on the complete suppression of his private self. A third theme is the danger of scientific progress when it crosses moral boundaries. Unlike the scientist in Mary Shelley's "Frankenstein", who breaks biological laws, Jekyll interferes with the psychological and moral nature of human beings. In both texts, the scientist is ultimately destroyed by his own creation, but in "Jekyll and Hyde" the link between creator and creature is absolute: they are the same person.