The Speckled Band - S1.E1

Helen Stoner needs the great man's help. She lives in a country mansion with her flamboyant and sinister guardian Grimesby Raylott, who has travelled abroad and brought home some souvenir livestock. Recently her sister Julia, about to be married and made by Raylott to sleep in a bed that was screwed to the floor, died in mysterious circumstances. Her final words referred to a "speckled band." Helen is fearful for her own safety and Holmes and Watson investigate.