All entrances to the study where the body was found were locked from the inside. The future college president and groom-to-be had no known cause for suicide, yet no clues point to a murder. Was Anita, the eponymous Mystery Girl, who is rumored to have been romantically involved with the dead man, somehow implicated in his death? Love letters between the two of them point to her potential guilt. And yet she seems incapable of such a crime. It's up to Detective Fleming Stone to decipher the story's twin puzzles; the mystery of the locked-room death and the true nature of ... .