This story is a fascinating example of the difference between tone and style. While James adopts a highly emotional, somewhat melodramatic, and intensely personal tone in writing the Governess's narrative, he maintains a style that is tightly reined-in and highly structured.
We get the feeling simultaneously that the narrator (the Governess) is gradually losing control, while the author (James) consistently works to create the illusion of lost control.
James's amazing use of pacing and his masterful creation of suspense is evident most clearly at the end of the story. The chapters grow shorter and shorter, building to the final moment (Chapter Twenty-Four), in which Quint appears for the last time, and Miles unexpectedly expires—and then it just stops.
Upon a first read, the average reader thinks, "What? That's not what I was waiting for. Thanks a lot, Henry." However, the more you ponder this ending, the more absolutely perfect it is—by not revealing anything at all, James allows his readers to keep mulling it over in their minds. Though at first it seems to be an incredibly flawed conclusion, perhaps more in keeping with the lack of control demonstrated in the Governess's voice, we ultimately see that James knew exactly what he was doing here, and that the whole story is constructed to culminate in this moment of shock and frustration.