When Ralph Black, chain store magnate, is found shot by his own gun in his locked library in his palatial home, the New York Police Department pronounces it suicide. However, his family members believe he was murdered.

His sister in England, Maria Black, M. A., Headmistress of a girls' school, wants to discover the truth. She travels to America, and with her penchant for solving crimes, sets to work to trace the mysterious plot against Ralph. Can she unmask the amazing truth about her brother's death? Or will the first case of "Black Maria" also prove to be her last? Black Maria, Book One.