The Adventure of the Speckled Band by Sir Arthur Conan Doyle is a mystery story featuring Doyle's famous fictional detective Sherlock Holmes and his loyal and faithful companion and chronicler Dr. Watson.
In this story, Holmes' client is Miss Helen Stoner. Her mother is dead and her sister, who was about to be married, died recently. She lives with her evil stepfather, Sir Grimesby Roylott, an English doctor, who met and married her mother in India. Sir Grimesby Roylott apparently murdered his butler in a fit of rage while in India and was forced to return to England to avoid prosecution.
Within the plot, this incident has two purposes. First, it shows evidence of Roylott's violent temper and second, it brings Miss Stoner into the orbit of Sherlock Holmes.