The Sign of the Four · Chapters
Chapters explained
Chapter companions for The Sign of the Four by Arthur Conan Doyle.
Chapter 1
The Science of Deduction
Watson observes Holmes injecting cocaine and confronts him about his drug use. Holmes defends his need for mental stimulation and explains his unique role as the world's only consulting detective. He criticizes Watson's romanticized account of their earlier case, then demonstrates his deductive method by analyzing Watson's brother's watch. The chapter ends with the arrival of Miss Mary Morstan.
Chapter 2
II: The Statement of the Case
Miss Mary Morstan visits Sherlock Holmes and Dr. Watson at 221B Baker Street to present a strange mystery. Her father, Captain Morstan, disappeared ten years ago after returning from India. Since then, she has received a valuable pearl each year on the same date, and today she receives a letter asking her to meet at the Lyceum Theatre. Holmes agrees to take the case and invites Watson to accompany them.
Chapter 3
In Quest of a Solution
Holmes deduces that Major Sholto's death in 1882 is connected to Captain Morstan's disappearance and the annual gifts to Miss Morstan. Miss Morstan shows Holmes a mysterious paper with a diagram and the names 'The sign of the four—Jonathan Small, Muhammad Singh, Abdullah Khan, Dost Akbar.' The trio embarks on a cab ride through foggy London to an unknown destination, eventually arriving at a house where a Hindu servant greets them.
Chapter 4
IV: The Story of the Bald-Headed Man
Thaddeus Sholto recounts his father's deathbed confession about Captain Morstan's accidental death and the hidden Agra treasure, revealing a mysterious intruder and the phrase 'The Sign of the Four'.
Chapter 5
The Tragedy of Pondicherry Lodge
Holmes, Watson, and Miss Morstan accompany Thaddeus Sholto to Pondicherry Lodge, where they discover his twin brother Bartholomew dead in a locked room, with a poisoned thorn in his neck and the note 'The sign of the four' beside him. The treasure is missing, and Thaddeus is distraught with fear of suspicion.
Chapter 6
VI: Sherlock Holmes Gives a Demonstration
Holmes demonstrates his deductive methods to Watson by reconstructing the crime scene at Bartholomew Sholto's room. He identifies the wooden-legged man's entry via the window with an ally's help, discovers a trapdoor to the roof, and finds tiny bare footprints suggesting a child-like accomplice. He also notes a creosote spill that can be tracked by a dog. Holmes sends Watson to fetch Toby, a scent hound, while he plans to question the servants and observe Inspector Jones.
Chapter 7
VII: The Episode of the Barrel
Watson escorts Miss Morstan home, reflecting on his growing feelings for her and the barrier of the Agra treasure. He then retrieves Toby from Mr. Sherman, returns to Pondicherry Lodge, and assists Holmes in analyzing the crime scene. Holmes deduces the involvement of Jonathan Small and a barefoot accomplice, and they set off with Toby to track the suspects.
Chapter 8
VIII: The Baker Street Irregulars
Holmes and Watson read a newspaper article praising Athelney Jones's arrest of Thaddeus Sholto and others. Holmes summons the Baker Street Irregulars, led by Wiggins, to search for the steam launch Aurora and its owner Mordecai Smith. Watson reflects on his personal stake in recovering the treasure for Miss Morstan. Holmes deduces that the mysterious assailant is a native of the Andaman Islands based on footprints and weaponry. Later, Toby loses the scent at a creosote crossing, but Holmes redirects the search to the riverside, where they learn from Mrs. Smith that her husband has left with a wooden-legged man in the Aurora.
Chapter 9
A Break in the Chain
Watson awakens to find Holmes frustrated by a lack of progress in the case. Holmes sends Watson to visit Mrs. Cecil Forrester and Miss Morstan, while he himself goes undercover as an elderly sailor to gather information. Athelney Jones arrives, and Holmes reveals his disguise, then outlines a plan to capture the criminals and recover the treasure.
Chapter 10
X: The End of the Islander
Holmes, Watson, and Athelney Jones dine together before embarking on a river chase to intercept Jonathan Small and his accomplice. Holmes explains his deductions leading to the launch's location at Jacobson's Yard. They pursue the Aurora on the Thames, with Holmes having arranged a sentry to signal when the suspects depart.
Chapter 11
XI: The Great Agra Treasure
Jonathan Small is captured and brought aboard the police launch. He recounts his role in the events, blaming Tonga for Bartholomew Sholto's death and expressing regret over the curse of the Agra treasure. Holmes and Athelney Jones discuss the chase. Watson is entrusted with the treasure box and brings it to Miss Morstan. Upon opening the box, they discover it is empty. Watson confesses his love for Mary Morstan, and she reciprocates, feeling relieved that the treasure is gone.
Chapter 12
The Strange Story of Jonathan Small
Jonathan Small recounts his life story, including his service in India, the murder of Achmet for the Agra treasure, his imprisonment, escape with Tonga, and his relentless pursuit of revenge against Major Sholto. He reveals that he threw the treasure into the Thames to prevent it from falling into the hands of Sholto's or Morstan's kin.
