About This Book:
A young lady, Mary Morstan, contacts Sherlock Holmes for his help regarding her father, who disappeared 10 years ago. Since his disappearance she has been receiving a valuable pearl by post annually from an unknown person. Together with his staunch comrade , Dr. John Watson, and a mutt named Toby, Homes tracks down the secret of the sign of four which leads Holmes and Dr. Watson into an intricate plot regarding a lost trasure belonging of four convicts on the Andaman Islands.