What is the author's tone in the novel, Two Words?

The story begins with an optimistic and passionate tone. It establishes Belisa Crepusculario’s origins and how she came to be a seller of words. Moreover, the narrator, limited to Belisa Crepusculario’s perspective, demonstrates the passion that Belisa Crepusculario feels towards her vocation. However, the story takes a darker tone when the narrator delves deeper into Belisa Crepusculario’s childhood.