Thus far in The Mill on the Floss, the novel has mainly been set at the mill or nearby, with the exception of Tom's school years at Lorton. With the opening of Book Sixth, however, the setting shifts to St. Ogg's, and with the setting change the novel's social background widens. The early dramas of Maggie's life played out only against the backdrop of her family, immediate and extended, but in St. Ogg's the presence of a whole community, and an accompanying set of social values and conventions is implicit. Just as Maggie seems to be more beautiful in her worn clothing, she also gains in appeal against the social backdrop of St. Ogg's. Because she is not studied in high societal conventions, her innocence and genuineness make her seem harmless (and therefore appealing) to competitive women and freshly attractive to men.

Book Sixth reintroduces Lucy Deane as a character. As children, Lucy stood for Maggie's opposite—light where she was dark, agreeable where she was contrary, docile where she was impetuous. In their maturity, the polarity between Lucy and Maggie still remains to some extent—Lucy enjoys leisure and money while Maggie works for a living. Lucy has remained petite where Maggie has grown tall. During their childhood, Maggie was never quite jealous of Lucy herself but often envied what Lucy had—the stature and features of a little queen or Tom's attention. Here again, Maggie has no direct enmity for Lucy, but Maggie is potentially put in a position of envy as regards her lifestyle and relationships.

Book Sixth introduces us to Stephen Guest. Stephen is depicted as overly self- assured and artificial, yet he is also shown to be perceptive. Stephen and Maggie's mutual interest seems a related to a sense of novelty on each side—Stephen has never met a woman as frank and earnest or from the same social background as Maggie, and Maggie has never enjoyed the close proximity of a strong male presence. Stephen's near obsession with her upon their first meetin is connected to the quality of Maggie's eyes. As they were in the descriptions of her as a child Maggie's eyes continue to be associated with some sort of witchcraft, or at least, power over others.

As becomes clear, Philip will also reappear in this book. Maggie's struggles remain mainly internal but also become externalized to some extent in Book Sixth, as embodied by three very different men—Stephen, Philip, and Tom.