A brief early American detective novella written in 1883 by Anna Katharine Green that tells the story of a detective who arrives in a small town in Massachusetts in an attempt to investigate counterfeiters possibly connected to a series of mysterious letters addressed only to X Y Z. While he is questioning the postmaster, he learns of the Benson family and their super secretive lifestyle. They are rich and reclusive. The detective feels there is something amiss and switches his investigation to them the letters and counterfeiting is dropped. That eventuates in murder. He steps into the very shoes of the person being framed for the crime, with some interesting results.