Utterson and Jekyll's butler eventually break into Jekyll's laboratory, where they find Hyde's body wearing Jekyll's clothes. They also discover letters from both Lanyon and Jekyll explaining the situation. Jekyll's letter reveals that he had developed a serum to separate the good and evil aspects of his personality. Taking the serum transformed him into Hyde, allowing him to indulge his vices without consequence to his reputation.

Initially, Dr. Jekyll could control the transformations, but eventually he began changing into Hyde involuntarily. Unable to find the ingredients to make more of the original effective serum, Jekyll realized he would soon be trapped permanently as Hyde. The letter ends with Jekyll's consciousness fading as Hyde takes over completely.

Themes

• Duality of human nature

• Good versus evil

• Effects of repression

• Science and its ethical limits

• Victorian social expectations and hypocrisy

• Identity and transformation

• Friendship and loyalty

Setting

The Strange Case of Dr. Jekyll and Mr. Hyde takes place in late Victorian-era London, specifically in the 1880s. This was a time of great scientific and technological progress but also of stark social contrasts between the wealthy and the poor. The story unfolds against the backdrop of a city grappling with rapid industrialization, overcrowding, and rampant poverty existing alongside areas of extreme wealth and refinement.

Much of the action occurs in the affluent neighborhoods of London, particularly the fictional upscale district where Dr. Jekyll's respectable townhouse is located. The story also ventures into seedier parts of the city, particularly Soho, where Mr. Hyde's residence can be found. This contrast between the genteel and squalid areas of London not only mirrors the dual nature of Jekyll/Hyde but also highlights the social divisions of the era.

Key locations in the story include Dr. Jekyll's home and laboratory, Mr. Hyde's dingy lodgings, the street where Sir Danvers Carew is murdered, and the offices and residences of Gabriel Utterson and Dr. Lanyon. The foggy, gas-lit streets of London serve as an atmospheric backdrop, shrouding the city in mystery and providing cover for Hyde's nefarious activities. This gloomy urban setting contributes significantly to the ominous mood and sense of duality that permeates the novella.

Characters

• Dr. Henry Jekyll: The protagonist. A respected London doctor, Dr. Jekyll is a conflicted man, struggling with the duality of his nature—his public face of respectability and his private indulgence in unnamed vices. He develops a potion to separate these aspects of his personality, transforming into the evil Mr. Hyde. As the story progresses, Jekyll loses control over his transformations and descends into madness.

• Mr. Edward Hyde: The evil alter ego of Dr. Jekyll. Mr. Hyde is described as ugly and deformed, representing the baser instincts of Jekyll's nature. He is cruel, violent, and completely amoral, committing terrible acts without remorse. As the story unfolds, Hyde grows stronger while Jekyll weakens, eventually taking over completely.

• Gabriel John Utterson: A lawyer and the narrator of much of the story. Utterson is a loyal friend to Jekyll and becomes increasingly concerned about his association with Hyde. He investigates the mystery surrounding Jekyll and Hyde, ultimately discovering the shocking truth. Utterson is rational, reserved, and represents the proper Victorian gentleman.

• Dr. Hastie Lanyon: A former colleague of Jekyll who disagrees with his scientific theories. Lanyon witnesses Hyde's transformation back into Jekyll, which shocks him so severely that he falls ill and dies. His written account provides crucial information about Jekyll's experiments.

• Richard Enfield: Utterson's cousin who first encounters Hyde after witnessing him trample a young girl. Enfield's story piques Utterson's curiosity about Hyde and sets the investigation in motion.

• Mr. Poole: Jekyll's loyal butler, who becomes increasingly worried about his master's behavior. He eventually seeks Utterson's help, leading to the final confrontation at Jekyll's laboratory.

• Sir Danvers Carew: A respected Member of Parliament who is brutally murdered by Hyde. His death intensifies the hunt for Hyde and increases Jekyll's desperation.

Quick facts

• Robert Louis Stevenson wrote the first draft of The Strange Case of Dr. Jekyll and Mr. Hyde in just three days while bedridden and feverish.

• Upon reading the first draft, Stevenson's wife Fanny criticized it as being too allegorical. Stevenson then burned the manuscript and rewrote the entire story in less than six days.

• Stevenson claimed the idea for the story came to him in a dream.

• The character name “Jekyll” was likely inspired by Stevenson's friend, Reverend Walter Jekyll.

• Some scholars argue the novella is an allegory for repressed homosexuality in Victorian society.

• The Strange Case of Dr. Jekyll and Mr. Hyde was initially published as a “shilling shocker”—a cheap paperback sold for one shilling.

• The novella was an immediate success, selling over 40,000 copies within the first six months of publication.

• The Strange Case of Dr. Jekyll and Mr. Hyde has inspired more than 120 stage and screen adaptations.

• The first stage adaptation premiered in 1887, just a year after the novella's publication.

• The 1931 film version won Fredric March an Academy Award for his portrayal of the dual title role. 

• Jekyll & Hyde, a musical based on Stevenson’s novella, premiered on Broadway in 1990.

• The phrase “Jekyll and Hyde” has entered popular vernacular to describe someone with a split personality.

About the Author

Robert Louis Stevenson (1850-1894) was a renowned Scottish novelist, poet, and travel writer. Blending elements of Romanticism with realism, his works often featured moral ambiguity and explored the duality of human nature. He is best known for his adventure novels Treasure Island and Kidnapped, as well as the gothic novella Strange Case of Dr Jekyll and Mr Hyde. In addition, his collection of poetry for children, A Child's Garden of Verses, remains popular to this day. 

Born in Edinburgh, Stevenson struggled with health issues throughout his life. Though he studied law at the University of Edinburgh, he chose to pursue a career as a writer. He traveled extensively and drew inspiration from his journeys, penning travelogues like Travels with a Donkey in the Cévennes. In 1880, he married American divorcée Fanny Van de Grift Osbourne and the couple eventually settled in Samoa, where Stevenson spent the final years of his life.

Beyond his writing, Stevenson was known for his charisma and wit. He formed friendships with many prominent literary figures of his day, including Henry James and G.K. Chesterton. Though he died at just 44 years old, Stevenson left behind a substantial body of work that continues to be widely read and adapted.