M
Mary Roberts Rinehart
A crime writer often called "the American Agatha Christie" (Wikipedia).
The Case of Jennie Brice
When young Jennie Brice vanishes, leaving behind only a blood-stained rope and towel, her landlady, Mrs. Pittman, suspects foul play. With no body to present to the authorities, Mrs. Pittman takes it upon herself to uncover the truth. This 1913 mystery, set in the historic Allegheny City, will keep you guessing as a determined woman tries to solve a perplexing disappearance.