New York: Doran, 1914. First Edition. Hardcover. Fine/Very good. Doyle incorporates a dual narrative structure, as the plot transitions from the present-day investigation by Holmes and Watson to a historical account of the events that led to the central crime. The additional space afforded by a full novel, gave Doyle the opportunity to change and blend genres within the two narratives, from a traditional Sherlockian detective mystery, to the suspenseful exposition. 1st edition of the seventh Sherlock Holmes book, and the 4th Holmes novel, preceding the London edition. Original cloth, fine in a dustjacket with some chips restored.