A Study in Scarlet introduced Sherlock Holmes, the great scientific detective, and his friend and chronicler, Dr. Watson. It tells of their first meeting. how they set up rooms together on Baker Street, and how they soon encountered a dramatic mystery which starts with a corpse found in a deserted house. The Sign of the Four is the second novel featuring Holmes and Watson and it presents Holmes with one of his greatest challenges - solving the theft of the great Agra treasure in India.In these two novels you have the foundation of the Sherlock Holmes legend.