The novel, "A Lost Lady," by Willa Cather sketches the changing relationship between a young boy in the western town of Sweet Water and a worldly but beautiful lady from California. The boy, Niel Herbert, was a little boy when he first saw Mrs. Forrester and believed her to be something "not of this world." By the time he is 19, Niel's opinion of Mrs. Forrester has changed to chagrin as he watches her flirt with boys that Niel believes are below her social class.

One of the themes that recurs in Cather's novels is the celebration of the pioneer. In this particular novel, Niel realizes that he is seeing the end of the glorious age of the pioneer. The men who claimed land in the west and tamed that land grow old during Niel's youth and early adulthood. He watches as their pioneer dreams are dashed by dwindling incomes and failing health. One example of these pioneers is Captain Daniel Forrester. His high moral standards will not allow him to remain rich while those who depended on him to protect their money lose most of what they have. As a result, Mr. Forrester and his wife are forced to rent part of their property to a crude man who destroys its beauty and encourages Mrs. Forrester to invest money in illegal ventures.

By the conclusion of the novel, Niel finally determines that he is angry with Mrs. Forrester for her determination to live and go on with her life despite the death of her husband. While the people of the town are talking about Mrs. Forrester because of her habit of inviting young men to her house for dinner, she believes that she is doing what is best for them by sharing with them the ways of the life she knew. Niel, who had taken off a year from school to care for the Forresters during Mr. Forrester's last days, feels the time he sacrificed for Mrs. Forrester was wasted.

One of the challenges of the novel is for the reader to determine what type of relationship Niel hoped to have with Mrs. Forrester. He sees her as a friend, a mother figure, and as a woman that he loves deeply. When Niel sneaks over to the Forrester home one morning when Mr. Forrester is away on business, he is upset to find her alone with another man. Similarly, after the death of Mr. Forrester, Niel believes that with the right man, Mrs. Forrester could be saved. It should be considered as one reads that book that Niel believes he is this man capable of "saving" Mrs. Forrester.