The Diamond Mine is the story of Cressida Garnet, a wealthy soprano, and her exploitation by her family and by the men with whom she becomes romantically involved. Cressida spends the story aboard a liner explaining her romantic past to a cousin of her deceased first husband. She tells him about her second husband's infidelity and of her plans to marry a wealthy financier. The conclusion details Cressida's death during the sinking of the Titanic and her unhappy marriage to her third husband. Her descendants fight over her estate.