Initials only (Anna Katharine Green)

A detective story first published in 1911, it is one of the book of Ebenezer Gryce series, „Initials Only” deals with the case of beautiful young heiress Edith Challoner. She is murdered in the writing room of a luxury hotel while nobody is near her, and no shot is heard and no bullet found in the deadly wound. She is seemingly stabbed to death, yet no one was seen near her. How then was she killed? Among Miss Challoner’s personal belongings are found letters signed with initials only, O.B. Who is O.B., and what – if anything – does he have to do with her death? Sweetwater, the investigator, finds out the identity of O.B. Pretty soon, but instead of answering the questions the case poses, he only brings up more mysteries.