The Valley of Fear

The Valley of Fear, the last of the four Sherlock Holmes novels, ranks among Sir Arthur Conan Doyle's best work. The mystery begins with a coded warning of imminent danger, drawing the illustrious Sherlock Holmes and the faithful Dr. Watson to a secluded English country home.
A trail of bewildering clues-raincoats, dumbbells, a missing wedding ring-leads to sleuthing in the finest Holmesian tradition and the gripping backstory of a cult that terrorized a valley in the American West.
The Valley of Fear is loosely based on the real-life exploits of the Molly Maguires and Pinkerton agent James McParland. The story was first published in the Strand Magazine between September 1914 and May 1915.

Arthur Conan Doyle was the creator of Sherlock Holmes and one of the most popular writers of his era, with a writing career spanning from 1879 to 1930.