Key Themes & Exam Technique

Theme 1: Empire and Colonialism

The British Empire is not just a backdrop to The Sign of Four — it drives the entire plot. The colonial origins of the Agra treasure connect every crime in the novel to India. The treasure was stolen from a merchant during the Indian Rebellion of 1857. Major Sholto and Captain Morstan — British officers in India — became entangled in its story. Jonathan Small lost his leg serving the empire. Tonga was brought from the colonised Andaman Islands. The wealth that Victorians celebrated as a product of empire is shown by Doyle to be built on theft, violence and exploitation.

Watson himself embodies the empire’s human cost. He is a wounded veteran of the Second Anglo-Afghan War, injured at the Battle of Maiwand. Yet Watson does not question the empire — he is proud of his service. This tension is important for contextual analysis: Doyle does not explicitly criticise the empire, but the plot he constructs shows its destructive consequences. A strong answer identifies this implicit critique rather than simply stating “the novel is about the empire.”

Theme 2: Justice and Revenge

Who is truly guilty in The Sign of Four? The question is more complex than it first appears. Small murdered the merchant and orchestrated Bartholomew’s death. But Sholto betrayed Small and stole the treasure. The original merchant was carrying wealth extracted from colonial India. Doyle complicates the idea of justice by showing that every act of theft and violence flows from an earlier injustice.

Holmes restores a kind of order: Small is captured, the mystery is solved. But the treasure is lost, Tonga is dead without mourning, and the underlying injustice of empire remains untouched. Doyle suggests that the justice system can solve individual crimes but cannot address the systemic injustice that created them. This is sophisticated territory for an exam essay: you can argue that Doyle both supports and questions the idea of justice.

Theme 4: Science and Reason

Holmes embodies the Victorian faith in reason. His deductive method is essentially the scientific method applied to crime: observe, hypothesise, test, conclude. His superiority over Athelney Jones demonstrates that evidence-based reasoning is more effective than assumption. Doyle, a trained doctor, champions this worldview through his hero.

However, Doyle also shows the limits of pure reason. Holmes cannot sustain human relationships. He dismisses Watson’s emotions with the cocaine syringe. His brilliance brings no personal fulfilment — only temporary relief from boredom. The cyclical structure (cocaine to cocaine) suggests that reason alone cannot create a meaningful life. Watson, with his warmth and capacity for love, achieves something Holmes cannot.

Theme 5: Love and Relationships

The romance between Watson and Mary Morstan runs parallel to the detective plot. Watson is attracted to Mary from the moment she arrives, but class anxiety holds him back — if the treasure is found, she would be wealthy and ‘above’ him. When the treasure is lost, Watson is relieved — “the golden barrier was gone from between us” — and he gains something more valuable. Doyle uses the romance to argue that human connection matters more than material wealth.

Holmes, by contrast, is entirely indifferent to love. When Watson announces his engagement, Holmes reaches for the cocaine. This juxtaposition at the novel’s close is structurally deliberate: Doyle places the two outcomes side by side to highlight what each character values and what each character lacks.

Key Quotations to Learn

Most nineteenth-century novel exams are closed book, but the extract is printed for you. For the ‘novel as a whole’ part of your response, you need to refer to events, characters and ideas from other parts of the text. Memorising a few key quotations will strengthen your response significantly, even though precise wording is not required.