Alias Agnes details the story of Jane Tucker, who took a job as an undercover detective with a ten-week mission. Her target: Madeleine Pollard, former mistress of Congressman William C. P. Breckinridge, whom she had sued for breach of promise when he failed to marry her. Exploring the intricacies of this trial and a scandal that captivated the nation, author Elizabeth A. DeWolfe demonstrates that a shared lack of power did not always lead to alliances among women.