Chapter 1: Story of the Door

The novella opens with Mr. Utterson, a reserved and serious lawyer, walking through the streets of London with his friend Mr. Enfield. They pass a mysterious door, prompting Enfield to recount a disturbing incident: he once saw a strange, sinister man, later identified as Mr. Hyde, trample a young girl in the street. Instead of fleeing, Hyde paid off the girl’s family with a cheque signed by the respected Dr. Jekyll. Enfield and Utterson agree that there is something deeply unsettling about Hyde’s presence, describing him as deformed, though they cannot explain why [1].

Chapter 2: Search for Mr. Hyde

Utterson, disturbed by Enfield’s story, examines Dr. Jekyll’s will, which states that in the event of his disappearance or death, all his belongings will pass to Hyde. Concerned, Utterson visits Dr. Lanyon, a fellow doctor and former friend of Jekyll, who dismisses Jekyll’s scientific experiments as "unscientific balderdash" [2].

Utterson then seeks out Hyde and is horrified by his unnatural presence, describing him as giving "an impression of deformity without any nameable malformation" [2]. He is disturbed by Jekyll’s apparent connection to Hyde and vows to uncover the truth.

Chapter 3: Dr. Jekyll Was Quite at Ease

Utterson confronts Jekyll about Hyde, but Jekyll reassures him that everything is under control and that he has "a very great interest in that young man" [3]. However, his nervous demeanor suggests he is hiding something. Jekyll insists that Hyde must be left alone, asking Utterson to respect the terms of his will.

Chapter 4: The Carew Murder Case

Nearly a year later, London is shocked by a brutal crime. Sir Danvers Carew, an elderly and respected man, is murdered in the street. A maid witnesses the attack and describes how Mr. Hyde, in a sudden fit of rage, savagely beats Carew to death with a cane before fleeing [4]. The police find the murder weapon—a broken cane that once belonged to Jekyll—and a letter addressed to Utterson on Carew’s body.

Utterson leads the police to Hyde’s residence, but Hyde is nowhere to be found. His servants claim they haven’t seen him for days, and his home is found in disarray, suggesting a hurried departure.

Chapter 5: Incident of the Letter

Utterson visits Jekyll, who now appears sickly but insists that he has severed all ties with Hyde. Jekyll provides Utterson with a letter supposedly written by Hyde, stating that he is disappearing forever. However, Utterson’s clerk notices that Hyde’s handwriting bears an uncanny resemblance to Jekyll’s, only slanted differently [5]. This raises further suspicions about the connection between the two men.

Chapter 6: Remarkable Incident of Dr. Lanyon

For a time, Jekyll seems to return to his old self, hosting dinners and engaging with friends. However, he soon withdraws into seclusion once again. Around the same time, Dr. Lanyon, once a healthy man, falls gravely ill. Before dying, he leaves Utterson a sealed letter, instructing him not to open it until after Jekyll’s death [6].

Utterson attempts to visit Jekyll, but his servant, Poole, informs him that Jekyll refuses to see anyone.

Chapter 7: Incident at the Window

During a walk, Utterson and Enfield pass Jekyll’s house and see him at his window. He briefly converses with them but suddenly shuts the window in terror, as if he has seen something horrific [7]. This bizarre behavior deepens Utterson’s suspicions.

Chapter 8: The Last Night

Poole, now desperate, seeks Utterson’s help, convinced that something terrible has happened to Jekyll. The two men break into Jekyll’s laboratory and find Hyde’s lifeless body on the floor, having committed suicide with poison. Jekyll, however, is nowhere to be found. A note from Jekyll instructs Utterson to read Dr. Lanyon’s letter and another document written by Jekyll himself [8].

Chapter 9: Dr. Lanyon’s Narrative

In Lanyon’s letter, he recounts how he received a mysterious request from Jekyll, asking him to retrieve a drawer of chemicals from his laboratory and give them to a stranger. That stranger turned out to be Hyde. Before Lanyon’s eyes, Hyde drank the potion and transformed into Jekyll, revealing his horrifying secret. The shock of witnessing this unnatural transformation led to Lanyon’s rapid decline and eventual death [9].

Chapter 10: Henry Jekyll’s Full Statement of the Case

Jekyll’s confession reveals the truth: in an attempt to separate his good and evil sides, he developed a potion that allowed him to transform into Mr. Hyde, an embodiment of his darkest desires. At first, he enjoyed the freedom Hyde provided, committing immoral acts without consequence. However, Hyde’s influence grew stronger, and Jekyll found it increasingly difficult to control the transformations.

Eventually, he began changing into Hyde involuntarily, even without taking the potion. Realising he could no longer repress Hyde, and with no more of the key ingredient needed for the potion, Jekyll saw no way out. With his final moments spent as Hyde, he took poison, choosing death over a life permanently trapped in his monstrous form [10].

The novella ends with the chilling realisation that Jekyll’s experiment has ultimately led to his ruin, serving as a cautionary tale about the dangers of unchecked scientific ambition and the duality of human nature.