The denouement is arguably the most important and most impactful stage in most of Hemingway's short stories. It is in the denouement stage of the story that there is often a dramatic revelation, climax, or a resolution, whereas the other stages of his stories are usually focused on establishing character, setting, or mood.
If we take the short story "Cat In The Rain," for example, there is in the denouement of the story a climax, or rather an anti-climax, which perfectly encapsulates the relationship between the two protagonists. The relationship between the protagonists, a husband and wife, seems to be falling apart throughout the story. In the denouement, the relationship seems about to end and then is saved, at least for a little while longer, by the maid bringing to the wife the cat that she has wanted throughout the story. In this moment, Hemingway makes the point that the relationship between the husband and the wife is founded upon nothing more than fleeting, trivial distractions, such as the cat. The denouement of the story thus creates a neat resolution, whereby the reader understands the relationship for what it is.
In other stages of the story, before the denouement, Hemingway focuses on characterization and mood. For example, at the beginning of the story, Hemingway tells us repeatedly that it is raining.The rain collects in "pools on the gravel paths" and "drip(s) from the palm trees." Hemingway also describes a "war monument" and the empty public square. The images of the rain and the empty public square suggest a dull, lifeless mood, and the "war monument" suggests conflict and battles. These aspects of the setting thus help to reflect the relationship between the husband and the wife and, in turn, help to set up the resolution in the denouement of the story.