A tempestuous girl from the swamps ignites passions when she moves into the business world.

In the rural town of Braddock, North Carolina, newcomer Dr. Saul Manfred is curious to meet Ruby Corey, a spirited beauty who intrigues Saul despite the fact that the class-conscious citizens of Braddock disdain her for having been born on the "wrong side of the tracks." Jim Gentry, the richest man in town, takes Saul to the hunting lodge run by Ruby's father Jud, and there Saul meets influential townsmen Judge Tackman, Clyde Pratt, Neil Fallgren and Cullen McAuliffe. Saul, who has admired Ruby from afar, is shy with her, but is nonetheless jealous of her obvious attraction to Boake Tackman, her high school sweetheart, who has just returned from a long stay in South America. Ruby's mother and religious brother Jewel warn her that Boake, who is from a poor but aristocratic family, will toss her aside as he did before, but Ruby is determined to make him marry her. During dinner, Boake explains his plan to drain his family's salt water swamped land and raise crops, and Jim offers to help him financially. Later, Jim tells Saul that when Ruby and Boake were in high school, Boake tried to take advantage of her and Ruby stabbed him with an oyster knife. Jim and his invalid wife Letitia then took Ruby in for a couple of years to protect her, and Letitia taught Ruby gracious manners and how to run a large house. Ruby had to return to the lodge, however, when Jud needed help, and now Jim wonders if it was unkind to give Ruby a glimpse of a life she can never have. Boake and Ruby's antagonistic, obsessive relationship intensifies the next day, when Ruby slips away from Saul during a duck hunt to meet with Boake. Ruby rebukes Boake for taking her for granted, and is angered later that day by Boake's deferential treatment of Tracy, McAuliffe's daughter. Despite everyone's assumption that Tracy and Boake will marry, Ruby pursues Boake and enjoys a tempestuous affair with him. Boake, who is making a success of his land reclamation business, eventually tells Ruby that he is engaged to the wealthy Tracy, and Ruby angrily rejects his suggestion that they continue seeing each other after the wedding. Soon after, Saul summons Ruby to town to care for Letitia, who is dying. Letitia is comforted by her last fews days with Ruby, and after Letitia dies, Jim proposes to Ruby. Ruby is hesitant, as she wonders if Jim will someday believe that she only married him for his money or to spite Boake, but Jim convinces her of his love, and the couple marry in New York. Despite Jim's prominence in the community, Ruby is snubbed by Braddock's oldest families, which irritates Jim. Then, one night at the country club, Ruby and Boake engage in a slow, romantic dance, and the jealous Jim provokes a fistfight with Boake. Jim and Ruby exchange harsh words, but the next day, while they are sailing, Ruby assures Jim that she does love him. Their reconciliation is short-lived, however, as a sudden wind arises and Jim is swept overboard. Despite Ruby's genuine grief over her husband's death, everyone in Braddock assumes that she murdered Jim. Saul stands by Ruby, but is astonished as, in revenge, she begins to foreclose on the many businesses to which Jim leant money. Soon, virtually all the businesses in Braddock are either shut down or are in debt to Ruby, for which Jewel castigates her. Ruby bitterly replies that she is merely getting back at the people who were cruel to her, and soon after, Boake comes to the Gentry mansion. Ruby offers to forgive his loan from Jim and expresses her desire to rekindle their relationship, but Boake coldly refuses both offers. Infuriated, Ruby not only assumes ownership of Boake's land but stops the reclamation process so that the land is once again covered by salt water. Crushed by his loss, Boake goes with Ruby to the Coreys' hunting lodge, where he forcefully resumes their romance. The next day, while they are duck hunting in the swamp, Ruby is unnerved by Boake's intimidating manner. Boake is softened by Ruby's heartfelt apology, however, and ruefully wonders how things would have differed if they had been social equals. Suddenly, a bullet whizzes by as Jewel, unbalanced by his obsession with Ruby's "sins," tries to murder his sister and her lover. Jewel succeeds in wounding Boake, after which Ruby shoots and kills her brother, then shoves his body into the swamp. Cradling the dying Boake, Ruby sobs, and years later, the embittered Ruby pilots a fishing boat and lives a reclusive life to atone for her past willfulness.