After Charles walks Ernestina home and they are alone, Ernestina breaks down in tears. She has discredited Mary, the kitchen maid to whom Sam is attracted. Ernestina has insinuated that Mary has loose morals, whereas Charles has been encouraging Sam’s pursuance of Mary, whom Charles had thought was charming. Charles had chastised Ernestina for her quick and negative judgment of Mary. Ernestina realizes how poorly she acted and feels ashamed, mostly because it has caused a disagreement between her and Charles. To prove she is repentant, Ernestina later offers one of her dresses to Mary, whose wardrobe is basically limited to work clothes. Ernestina fears losing Charles and promises him that she will not be so petty in the future.

Later, when Charles returns to his home, he warns Sam that he is not to break Mary’s heart. Mary is a decent young woman who deserves only Sam’s sincerest affections. After Sam admits that he is in love with Mary, Charles tells Sam that he will seek Mrs. Tranter’s permission for Sam to court Mary.

As a way of making amends with Charles, Ernestina pays very close attention to Charles’s needs in the days that follow their quarrel over Mary and Sam. Charles begins to understand that Ernestina was at first merely in love with the idea of being married. But now she is becoming more aware of the man she is to wed. However, Charles becomes somewhat bored by all the attention. Ernestina insists that Charles keep company with her every day. Charles, who has long enjoyed his bachelorhood, begins to feel fenced in with all this domestic attention.

To ease this feeling, one day Charles goes for a long walk through the woods again. He knows that Sarah, the French lieutenant’s woman, is on his mind, but he insists to himself that his real purpose for the walk is to search for fossils. However, when he comes to the spot where he saw Sarah asleep on the grass, he is disappointed that she is not there. Then he focuses his attention on the rocks.

Charles climbs the cliffs when he tires of his search. He is pleased to see Sarah on the path ahead; her coat has become entangled in some brambles. He is surprised to feel sensually aroused by the sight of her. When he walks up to her, he studies her appearance more closely than he has before. He concludes that she appears very intelligent as well as sensual. After his worldly travels, Charles also finds Sarah somewhat exotic; she looks less like a common British woman and more foreign. Her features make her look tomboyish but not in an unattractive manner; rather, they make her look strong.

Charles decides to be very honest with Sarah, although he barely knows her. He recently heard Mrs. Tranter talking about Sarah’s situation. Mrs. Tranter had made it clear that Sarah’s living with Mrs. Poulteney was not in Sarah’s best interest. After listening to Mrs. Tranter’s description of Mrs. Poulteney, Charles felt that she was a bigot, pretending to want to do good for someone in need but prejudging and belittling Sarah at the same time. Charles suggests to Sarah that she allow Mrs. Tranter help her, which Mrs. Tranter had insinuated she was willing to do. Charles also tells Sarah that maybe she should move away from the area where everyone knows her only as the French lieutenant’s woman. He suggests that she should go to London, where he would help her find a job.

Sarah, however, tells him she cannot leave Lyme. When she looks out at the sea, Charles interprets her statement as her not wanting to leave because she still believes the French lieutenant will return one day. But Sarah tells him that is not the reason. She knows for certain that the lieutenant will never come back for her. She has found out that the lieutenant is married.

Charles is confounded as he watches Sarah walk away. He does not understand why Sarah would not want to leave. He wonders why she appears to want to suffer.