The Adventure of the Speckled Band by Arthur Conan Doyle

A terrified young woman seeks Holmes’s help after her sister dies under mysterious circumstances, whispering “the speckled band” before her death. Holmes and Watson uncover a sinister plot involving a venomous snake, a cruel stepfather, and a locked room. The plot builds tension through eerie details and a climactic confrontation. It’s one of Doyle’s most famous and chilling tales. A classic locked-room mystery with Gothic undertones and a satisfying resolution.