About the Book

The Sign of the Four is the second Sherlock Holmes novel. Its complex plot involves service in the East India Company, India, the Indian Rebellion of 1857, a stolen treasure, and a secret pact among four convicts and two corrupt prison guards.

It presents Sherlock Holmes' drug habit and humanizes him in a way that had not been done in A Study in Scarlet. It also introduces Doctor Watson's future wife, Mary Morstan.