When Miss Amelia Butterworth observes a couple entering the neighboring Van Burnam mansion, her instinct tells her that something isn’t right. Investigating, she discovers a woman’s body and realizes she has stumbled upon a murder, and that she’s a vitally important witness. But Miss Butterworth aspires to be more than simply a witness, however important—she sets out to solve the crime. Initially she works in competition with the famed New York detective, Ebenezer Gryce , but as the mystery deepens, nothing but their cooperation will lead to the truth.

With the creation of the character of Miss Butterworth, Anna Katharine Green anticipated by thirty years the advent of Agatha Christie’s more famous elder spinster and amateur sleuth, Miss Marple .