A Study in Scarlet

The first story about Sherlock Holmes, written by the 27-year-old doctor Arthur Conan Doyle, who had been captivated by writing since his university years, took him three weeks to complete.
Doctor Watson, returning to England after being wounded on the front,... is looking for an affordable apartment and finds one — at 221b Baker Street. His neighbor turns out to be a certain Mr. Sherlock Holmes, who, as it later becomes clear, assists the police in investigating particularly complex cases.
And very soon his help will be needed again: a man's body is found in an abandoned house. No signs of robbery or indications of violent death — only a bloody inscription on the wall...