"The Adventure of Charles Augustus Milverton" is a Sherlock Holmes short story by Sir Arthur Conan Doyle, first published in Collier's in the US on March 26, 1904, and in The Strand Magazine in the UK in April 1904. Part of The Return of Sherlock Holmes collection, the story follows Holmes as he is hired by Lady Eva Blackwell to recover compromising letters from Milverton, a notorious blackmailer whom Holmes finds more detestable than any criminal he has faced.