? A cryptic message. A missing father. A pact sealed in blood.

In The Sign of the Four, Sherlock Holmes faces a case like no other—a mystery that stretches from the foggy streets of London to the far corners of the British Empire. When Mary Morstan receives a series of strange pearls and a summons from an anonymous benefactor, she turns to Holmes and Dr. Watson for help.

What unfolds is a dazzling investigation involving stolen treasure, a secret alliance, and a chilling tale of vengeance from colonial India. As Holmes navigates riddles, poison darts, and a deadly pursuit along the Thames, Watson finds himself falling for Mary—a romance that will change his life forever.

? Why this novel is a classic:

Introduces Toby the tracking dog and Holmes' famous violin playing

Features one of Doyle's most complex plots and fast-paced action

Mixes detective work with adventure, romance, and imperial history

Marks the beginning of Watson's romantic arc

? Perfect for readers who love:

Sherlock Holmes novels and classic mysteries

Exotic settings and hidden treasure plots

British detective fiction with historical flair

Holmes & Watson's early adventures

? What readers are saying:

"Doyle combines mystery and adventure like no other—this is Holmes in full force." – Classic Crime Review

"A thrilling blend of treasure, betrayal, and clever deduction." – Amazon Reviewer

? Click "Buy Now" and follow Holmes through one of his most dangerous—and dazzling—adventures yet.