What are the most important scenes for major and minor character interactions?

In 's
novel , two significant scenes in parts 1 and 3 involve interactions
between the major characters Tommy and Kathy and the minor characters Miss Lucy and
Madame.

In chapter 3 of the novel, Tommy describes to Kathy a conversation
he had with Miss Lucy about creativity and donating. This conversation led Tommy and Kathy to
wonder if the two ideas were somehow connecteda thought that forms...