Holmes is hired by the débutante Lady Eva Blackwell to retrieve compromising letters from a blackmailer:
| Actor | Role |
|---|---|
 Eille NorwoodSherlock Holmes | Sherlock Holmes |
| HHubert WillisDr. John Watson | Dr. John Watson |
| TTeddy ArundellInsp. Hopkins | Insp. Hopkins |
| GGeorge FoleyMilverton | Milverton |
 Harry WorthButler | Butler |
 Toni Edgar-BruceLady Eva Bracknell | Lady Eva Bracknell |
| MMme. d'EsterreMrs. Hudson | Mrs. Hudson |
| EEdith BishopMaid | Maid |