Molly Ferguson’s comfortable life unravels when her Louisiana home is burned to the ground, her family murdered, and she is enslaved in a Baltimore brothel. Amidst the threat of the Civil War, Molly learns of secessionist plans to assassinate President-elect Abraham Lincoln as he makes his way to Washington for his inauguration. She’s manages to pass this information on to a Pinkerton agent posing as a client. Impressed with her fortitude and intelligence, the Pinkerton Agency arranges for Molly’s freedom and brings her under the tutelage of Mrs. Kate Warne, America’s first female detective. After they save Mr. Lincoln in Baltimore, Molly is sent by the Pinkerton Agency into the Deep South—where the Civil War now rages—a spy behind enemy lines.