April 1927. After months of rain, the Mississippi River has reached dangerous levels and the little town of Hobnob is at threat. Residents fear the levee will either explode under the pressure of the water or be blown by saboteurs from New Orleans, who wish to save their own city.

But when an orphaned baby is found the lives of Ingersoll, a blues-playing prohibition agent and Dixie Clay, a bootlegger who is guarding a terrible secret, collide. They can little imagine how events are about to change them and the great South forever. For in the dead of night, after thick, illusory fog, the levee will break.