"The Adventure of the Speckled Band" is a Sherlock Holmes short story by Sir Arthur Conan Doyle, first published in The Strand Magazine in February 1892. It appears as the eighth entry in The Adventures of Sherlock Holmes collection. Often cited as one of Doyle's best works, the story is a dark, Gothic-tinged mystery centered on a young woman who seeks Holmes's help after the sudden and unexplained death of her twin sister. Set in a decaying country estate, the case unfolds as a classic locked-room mystery involving family secrets, inheritance, and mortal danger.