In a nation divided, no secret is safe...

September 1862. As war tears the country apart, Hattie Logan is running from her past. Escaping a dull life of wealth and privilege, she joins the Pinkerton Detective Agency. Stationed in the Civil War hotbed of Washington City, she intercepts Confederate mail and puzzles out ciphers. But she longs to do more.

Passed over for an enticing assignment, she jumps at the chance to spy with Thom Welton, the courier who runs mail between North and South. Posing as his wife, she crosses into enemy territory, where she finds herself falling in love.

A decoded letter revealing a family secret forces Hattie to confront a devious double agent. Betrayed by a fellow spy, she and Thom come into Confederate crosshairs. Could the past she's running from be the key to saving them?

A sweeping story of courage and resilience inspired by the authentic adventures of historical women spies.