Adventures of Sherlock Holmes, The - The Adventure of the Speckled Band

"The Adventure of the Speckled Band" is one of 56 Sherlock Holmes short stories by Arthur Conan Doyle. Holmes and Watson encounter a young woman who feels mortally threatened by her stepfather. She tells of her twin sister's mysterious and untimely death two years earlier- and her dying words, "The speckled band!". What does it all mean? Holmes agrees to take the case.