When Abraham Lincoln becomes president-elect of the United States, slave owners in the South begin rumbling about secession–and assassination. Kate Warn, the first and only female detective in Allan Pinkerton’s National Detective Agency, is enlisted with several other spy agents to infiltrate the groups heading up the assassination plot and stop them. Hattie MacLaughlin becomes the second female detective, Kate’s reluctant protege, and immediately finds herself thrust into the deep end of the spy-game pool, where she must shed her timidity and inhibitions in her fight to survive. As the mysterious Prophet manipulates his followers to take down Lincoln for the betterment of America and the future of slavery and civilization, Kate and Hattie both find themselves observing firsthand the horrors of slavery and facing their own inner demons.