The Sign of Four

The Sign of Four is a detective novel written by Arthur Conan Doyle and originally published in 1890. It is the second novel starring Sherlock Holmes.

Sherlock Holmes and his inseparable companion, Dr. Watson, investigate a case involving murder, treasure and a complex conspiracy in which the two will have to go in search of a group of thieves.

Set in and around London in the late 19th century, the novel is known for its complex plot and its exploration of the relationship between Holmes and Watson. It is one of the few long novels about Sherlock Holmes, as most of his stories are short stories.

"Sherlock Holmes took his bottle from the corner of the mantel-piece and his hypodermic syringe from its neat morocco case. With his long, white, nervous fingers he adjusted the delicate needle, and rolled back his left shirt-cuff. "