The hero of the novel, Joseph Frowenfeld, is a young scientist who moves to Louisiana to make his fortune. An outsider, Frowenfeld learns the ways of the Creoles and of the few Americans in the city through his acquaintance with the proud Grandissime family. He comes to know Honore Grandissime, the young leader of the clan, as well as his half-brother, a prosperous free man of color also named Honore, who has the power to rescue his relations from financial ruin.