The story of the three women who, according to General Ulysses S. Grant, helped the Northern states win the Civil War. At the center are a Virginia society lady, her unyielding mother, a former slave and ally, and Richmond's most notorious courtesan—four women who operated at the very heart of the Confederacy's power. Together, they develop their Underground Railroad operation into a daring and highly effective espionage network, risking their lives and freedom to protect the nation's future and safeguard American democracy.