This analysis was generated by AI from publicly available reader reviews, literary criticism, and book discussions. It has not been verified by a BookLens community reviewer and may contain errors. Be the first to verify →
Content snapshot
Flag an inaccuracy →What's in this book, at a glance — five things readers want to know before they start.
Violence
Barely any
Mild; period crime and adventure including a murder
Language
None
No strong language
Sexual Content
None
No sexual content
Substance Use
Barely any
Mild; Holmes's cocaine use is referenced
Emotional Intensity
None
No psychological concerns; classic detective fiction
What this book is about
The second Sherlock Holmes novel follows Holmes and Watson as they investigate a case brought to them by Mary Morstan — who has been receiving anonymous pearls for years and has now received a mysterious summons. The case involves the Agra treasure, a revenge plot reaching back to India, and Watson's fateful meeting with his future wife. One of the most entertaining entries in the Holmes canon.
Notes for sensitive readers
Reader-flagged moments and themes that may affect your experience.
Reader Verification
Be the first to verify
this rating
Have you read Sign of the Four? Submit a community rating to confirm or correct the AI estimate. Your review helps other readers make an informed choice.
Rate this book →Free · ~5 minutes · No account required
Similar reads
More Mystery books from the catalog.
Think this AI estimate is off?
Flag an inaccuracy →Where to Buy
Affiliate links — BookLens earns a small commission at no extra cost to you.