The Duchess of Wiltshire's Diamonds

Guy Newell Boothby (13 Oct 1867 – 26 Feb 1905) was a prolific Australian novelist and writer, noted for sensational fiction in variety magazines around the end of the nineteenth century. He lived mainly in England. He is best known for such works as the Dr Nikola series, about an occultist criminal mastermind who is a Victorian forerunner to Fu Manchu.
The Duchess of Wiltshire's Diamonds is classic Victorian detective novel by Guy Boothby. A real present for all lover of this genre, because Dr. Nikola, the detective investigating this case, was called a Holmes' rival for a reason.