Alison McNair is certain that she can be as shrewd as her favorite detective on TV, even without the help of the New York Police Department. She has her chance when her friend, Emmaline, sobs out the story of a terrible crime that is threatening her father's job. Together Alison, Emmaline, and Jeannie, Alison's sister, begin their sleuthing. They fearly tackle a problem that leads to some mysterious questions.
Have they stumbled into an organized crime ring? Will the "underworld" informant be able to unearth vital information for the girls? Will they be able to tail the strange person in the long black robe? Match wits with Alison and her friends as they follow a trail of bewildering clues!