Strange Case of Dr Jekyll and Mr Hyde[a] is an 1886 Gothic horror novella by Scottish author Robert Louis Stevenson.

It follows Gabriel John Utterson, a London-based legal practitioner who investigates a series of strange occurrences between his old friend, Dr. Henry Jekyll, and a murderous criminal named Edward Hyde.

Strange Case of Dr Jekyll and Mr Hyde is one of the most famous pieces of English literature, and is considered to be a defining book of the gothic horror genre.

The novella has also had a sizeable impact on popular culture, with the phrase "Jekyll and Hyde" being used in vernacular to refer to people with an outwardly good but sometimes shockingly evil nature.

According to author Jeremy Hodges,[5] Stevenson was present throughout the trial and as "the evidence unfolded he found himself, like Dr Jekyll, 'aghast before the acts of Edward Hyde'."

Moreover, it was believed that the teacher had committed other murders both in France and Britain by poisoning his victims at supper parties with a "favourite dish of toasted cheese and opium".

[6] The novella was written in the southern English seaside town of Bournemouth in Hampshire, where Stevenson had moved in 1884 to benefit from its sea air and warmer climate.

[11] Stevenson was friends with other homosexual men, including Horatio Brown, Edmund Gosse, and John Addington Symonds,[12] and the duality of their socially suppressed selves may have shaped his book.

After a while, Robert called her back into the bedroom and pointed to a pile of ashes: he had burnt the manuscript in fear that he would try to salvage it, and thus forced himself to start again from nothing, writing an allegorical story as she had suggested.

Scholars debate whether he really burnt his manuscript; there is no direct factual evidence for the burning, but it remains an integral part of the history of the novella.

Gabriel John Utterson, a reserved and morally upright lawyer, and his lighthearted cousin Richard Enfield are on their weekly walk when they reach the door of a mysterious, unkempt house located down a by-street in a bustling quarter of London.

Enfield recounts to Utterson that, months ago, in the eerie silence of three o'clock in the morning, he witnessed a malevolent-looking man named Edward Hyde deliberately trample a young girl after a seemingly minor collision.

Hyde brought Enfield to this door and gave him a cheque signed by a reputable gentleman later revealed to be Doctor Henry Jekyll, Utterson's friend and client.

A year later in October, a servant sees Hyde beat Sir Danvers Carew, another one of Utterson's clients, to death and leave behind half a broken cane.

For two months, Jekyll reverts to his former sociable manner, appearing almost rejuvenated, but in early January, he abruptly begins refusing all visitors, deepening the mystery and concern surrounding his behaviour.

Utterson and Poole forcefully break into the laboratory, their hearts pounding with dread, only to find Hyde’s lifeless body grotesquely draped in Jekyll’s clothes, a scene suggesting a horrifying and desperate suicide.

Lanyon's letter reveals his deterioration resulted from the shock of seeing Hyde drink an elixir that turned him into Jekyll.

Jekyll's letter explains he held himself to strict moral standards publicly, but indulged in unstated vices and struggled with shame.

Jekyll concludes by confessing that he is uncertain whether Hyde will face execution or muster the courage to end his own life, but it no longer matters to him.

Utterson is a measured and at all times emotionless bachelor – who nonetheless seems believable, trustworthy, tolerant of the faults of others, and indeed genuinely likeable.

After he witnesses the transformation process (and subsequently hears Jekyll's private confession, made to him alone), Lanyon becomes shocked into critical illness and, later, death.

At the time of his death, Carew is carrying on his person a letter addressed to Utterson, and the broken half of one of Jekyll's walking sticks is found on his body.

Literary genres that critics have applied as a framework for interpreting the novel include religious allegory, fable, detective story, sensation fiction, doppelgänger literature, Scottish devil tales, and Gothic novel.

The novella is frequently interpreted as an examination of the duality of human nature, usually expressed as an inner struggle between good and evil, with variations such as human versus animal, civility versus barbarism sometimes substituted, the main point being that of an essential inner struggle between the one and other, and that the failure to accept this tension results in evil, or barbarity, or animal violence, being projected onto others.

Banishing evil to the unconscious mind in an attempt to achieve perfect goodness can result in the development of a Mr Hyde-type aspect to one's character.

[20] This idea is suggested when Hyde says to Lanyon, shortly before drinking the famous potion: "your sight shall be blasted by a prodigy to stagger the unbelief of Satan."

As Stevenson's biographer Graham Balfour wrote in 1901, the book's success was probably due rather to the "moral instincts of the public" than to any conscious perception of the merits of its art.

Richard Mansfield bought the rights from Stevenson and worked with Boston author Thomas Russell Sullivan to write a script.

The lighting effects and makeup for Jekyll's transformation into Hyde created horrified reactions from the audience, and the play was so successful that production followed in London.

[38] There have also been many audio recordings of the novella, with some of the more famous readers including Tom Baker, Roger Rees, Christopher Lee, Udo Kier, Anthony Quayle, Martin Jarvis, Tim Pigott-Smith, John Hurt, Ian Holm, Gene Lockhart, Richard Armitage, John Sessions, Alan Howard, Rory Kinnear and Richard E. Grant.