Mystery, Murder, and a Hidden Treasure: Unpacking The Sign of the Four

Explore the enduring charm of Arthur Conan Doyle’s Sherlock Holmes through this thrilling Oxford Bookworms Level 6 adaptation.

An Iconic Detective and a New Case

Another gloomy London day sets the stage for one of Sherlock Holmes's most intricate adventures. In The Sign of the Four, Sir Arthur Conan Doyle’s master detective is more than just bored—he is verging on despondency. Holmes’s mind, sharp and unrelenting, needs challenge and stimulation, and after months without a case, his frustration begins to manifest in dark and disturbing ways. His loyal friend and flatmate, Dr Watson, becomes increasingly worried about Holmes’s well-being. This unsettling calm is soon broken, however, when a young woman named Miss Mary Morstan arrives at 221B Baker Street with a mystery that promises intrigue, danger, and perhaps even romance.

What follows is a gripping journey through hidden secrets, family betrayal, lost treasure, and cold-blooded murder. For advanced English learners at the CEFR C1 level, this adaptation in the Oxford Bookworms Library offers an engaging and accessible way to experience one of the most memorable cases in Holmes’s career.

A Mysterious Visitor and a Puzzle from the Past

Miss Morstan’s case is strange from the start. Ten years earlier, her father, a British army officer stationed in India, disappeared after returning to London. Since then, she has lived a quiet, solitary life—until four years ago, when she began receiving a single valuable pearl every year from an anonymous source. Now, the sender has requested a meeting, and Miss Morstan is afraid but curious. She seeks Holmes’s help in uncovering the truth.

As Holmes listens to her story, his mood visibly shifts. Here, at last, is a problem worthy of his talents. With Watson and Miss Morstan in tow, Holmes sets out to solve the riddle. Their investigation soon leads them into a web of long-buried secrets and crimes committed years ago in colonial India.

The Hunt for the Agra Treasure

At the heart of the mystery lies the legendary Agra treasure—a hoard of gold and jewels once belonging to an Indian prince, and allegedly stolen by a group of British soldiers during the Indian Rebellion of 1857. Among them was Miss Morstan’s father, Captain Arthur Morstan, and another officer, Major Sholto. The treasure was hidden, and after a violent argument between the two men, Captain Morstan vanished.

Holmes and Watson discover that Major Sholto had secretly kept the treasure and built a luxurious life from it. Before his death, he confessed his guilt to his sons but died before revealing the treasure’s location. His final words mentioned “the sign of the four,” a cryptic clue that leads Holmes further into the mystery.

Clues, Boats, and Betrayal

Holmes uses his extraordinary powers of deduction to trace a mysterious figure connected to the pearls. The chase leads the detectives down the River Thames, where danger waits on the dark waters. Holmes and Watson eventually uncover the involvement of a one-legged man, Jonathan Small, who claims to be one of the original “four” who discovered the treasure in India. According to Small, he was betrayed and imprisoned while others profited from their stolen fortune.

With the help of a native islander named Tonga, Small attempts to retrieve the treasure—but Holmes is always one step ahead. A thrilling boat chase ends in tragedy, with Tonga killed and Small captured. Small then reveals the complete tale of treachery, murder, and colonial greed behind the treasure’s history. To everyone’s shock, the treasure, once thought to be a source of unimaginable wealth, has been lost forever—thrown into the river by Small himself.

A Case That Changes Everything

While the Agra treasure is gone, something valuable remains: the bond between Watson and Miss Morstan deepens throughout the case. By the end of the story, Watson confesses his love for her and proposes marriage. The tale ends not with riches, but with emotional resolution—a rare moment of softness in the otherwise sharp and logical world of Sherlock Holmes.

Themes of Justice, Colonialism, and Human Nature

The Sign of the Four is more than just a detective story; it is a reflection on justice, morality, and the darker sides of human ambition. The tale shows how greed corrupts, how betrayal wounds, and how even the cleverest plans can collapse under the weight of human error. Doyle’s story also touches on British colonialism, portraying the chaos and exploitation that followed imperial ambitions in India.

This edition from Oxford Bookworms simplifies complex vocabulary and structures without sacrificing the depth and tone of the original. It’s an ideal read for advanced learners who want to explore English literature while also refining their reading comprehension and vocabulary.

Why Read The Sign of the Four at CEFR C1 Level?

For learners at the C1 level, The Sign of the Four offers a perfect blend of challenge and enjoyment. The story demands attention and inference, with nuanced dialogue and period-specific language that help develop reading fluency. Readers must follow Holmes’s deductions, interpret clues, and understand the motivations of a diverse cast of characters.

Moreover, the book introduces a range of vocabulary related to crime, investigation, emotions, and colonial history. It’s a great way for learners to expand their lexicon in a meaningful, contextualized way.

Vocabulary and Language Focus

Oxford Bookworms Level 6 readers are carefully graded to support language learning. In this adaptation, readers can expect to encounter and master vocabulary such as:

• deduction, motive, betrayal, treasure, confession, evidence, disguise, suspicion, and pursuit.

• Formal and descriptive expressions like "a trace of melancholy", "an air of authority", or "a shadow of doubt" enhance understanding of tone and mood.

• Idioms and figurative language that reflect 19th-century speech, which enriches students' cultural and linguistic awareness.

Each chapter is designed with learner support in mind, making the book not only enjoyable but also highly educational.

Conclusion: A Classic for Curious Minds

Sherlock Holmes: The Sign of the Four is a thrilling dive into the world of deduction, mystery, and adventure. With its rich plot, vivid characters, and intellectual challenges, it continues to capture the imagination of readers more than a century after its first publication. This Oxford Bookworms Level 6 edition presents the story in a way that is both accessible and stimulating for advanced English learners.

Whether you’re a fan of detective fiction, a lover of classic literature, or a language student looking to push your reading skills further, this book is a must-read. Holmes’s genius, Watson’s loyalty, and the tangled web of lies and longing will keep you turning pages—and sharpening your English—with every twist and turn.

Sir Arthur Conan Doyle British writer and physician. 

The Mastermind Behind Sherlock Holmes

Early Life and Education: The Making of a Literary Legend

Sir Arthur Conan Doyle was born on May 22, 1859, in Edinburgh, Scotland. Raised in a family with a strong artistic background, he exhibited an early passion for storytelling. His father, Charles Altamont Doyle, was an artist, while his mother, Mary Foley Doyle, was known for her love of books and storytelling. This maternal influence played a crucial role in shaping young Arthur’s imagination and literary inclinations.

Doyle pursued his education at Stonyhurst College before enrolling at the University of Edinburgh Medical School in 1876. During his time at university, he encountered Dr. Joseph Bell, a professor of medicine renowned for his keen powers of observation and logical reasoning. Bell's influence would later serve as the primary inspiration for Doyle’s most famous creation, Sherlock Holmes.

A Career in Writing: From Medicine to Mystery

Though Doyle trained as a physician and even set up his own medical practice, he found himself increasingly drawn to writing. His literary career took off in 1887 with the publication of A Study in Scarlet, which introduced readers to Sherlock Holmes and Dr. John Watson. The novel received moderate success, but it was not until the short stories published in The Strand Magazine that Holmes became a literary sensation.

With his keen intellect, unparalleled deductive reasoning, and meticulous attention to detail, Sherlock Holmes quickly became one of the most beloved fictional characters in literary history. Doyle’s masterful storytelling and ability to craft intricate mysteries kept readers eagerly awaiting the next installment of Holmes' adventures.

The Sherlock Holmes Phenomenon

Between 1887 and 1927, Doyle wrote four novels and fifty-six short stories featuring Sherlock Holmes. Some of the most notable works include:

• A Study in Scarlet (1887) – The first appearance of Sherlock Holmes and Dr. Watson.
• The Sign of the Four (1890) – A thrilling tale of treasure, betrayal, and revenge.
• The Adventures of Sherlock Holmes (1892) – A collection of twelve short stories, including classics like A Scandal in Bohemia and The Speckled Band.
• The Hound of the Baskervilles (1902) – Perhaps the most famous Holmes novel, featuring the eerie legend of a supernatural hound haunting the Baskerville family.
• The Return of Sherlock Holmes (1905) – Marking Holmes’ dramatic comeback after Doyle had originally killed off the character in The Final Problem (1893).

Despite the overwhelming popularity of Holmes, Doyle grew tired of his creation and wanted to focus on other literary pursuits. In an attempt to move on, he famously killed Holmes off in The Final Problem, only to resurrect him due to public demand.

Beyond Sherlock Holmes: Doyle’s Other Works

While Sherlock Holmes remains Doyle’s most enduring legacy, he was a prolific writer who explored various genres. His historical novels, such as The White Company (1891) and Sir Nigel (1906), showcased his passion for history and adventure. He also dabbled in science fiction with The Lost World (1912), a thrilling novel about an expedition to a prehistoric land inhabited by dinosaurs.

Doyle’s literary repertoire extended to horror, drama, and political writing. His short story collections, including Tales of Terror and Mystery, reflected his ability to weave suspenseful and eerie narratives.

A Man of Many Interests: Doyle’s Personal and Political Life

Beyond literature, Doyle led a fascinating life filled with diverse pursuits. He was a staunch advocate for justice, often using his investigative skills to help overturn wrongful convictions. One of the most famous cases he championed was that of George Edalji, a solicitor falsely accused of animal mutilation. Doyle’s efforts played a significant role in proving Edalji’s innocence and exposing flaws in the British legal system.

Doyle also had a deep interest in spiritualism. Following the tragic deaths of his son and brother during World War I, he became a devoted believer in the supernatural. He wrote extensively on the subject, engaging in debates and attending séances in hopes of communicating with the deceased.

Legacy and Influence

Arthur Conan Doyle passed away on July 7, 1930, leaving behind an unparalleled literary legacy. His creation, Sherlock Holmes, continues to captivate audiences through countless adaptations in film, television, and literature. From Basil Rathbone’s classic portrayals to Benedict Cumberbatch’s modern adaptation in Sherlock, Holmes remains an iconic detective who transcends generations.

Doyle’s influence extends beyond fiction; his meticulous approach to detective storytelling laid the foundation for modern crime fiction. Authors such as Agatha Christie and Raymond Chandler owe much to his pioneering work in the genre.

Conclusion: The Enduring Genius of Arthur Conan Doyle

Arthur Conan Doyle was far more than just the creator of Sherlock Holmes. He was a visionary storyteller, a champion of justice, and a man deeply fascinated by the unknown. His ability to craft engaging narratives filled with intrigue, intellect, and adventure has solidified his place as one of the greatest literary figures of all time. His works continue to inspire and entertain, ensuring that his legacy will live on for many generations to come.