Final answer:
The author uses the setting to establish the story's central conflict and mood, indicating a sense of loss and melancholy through descriptive details like the rain and the empty apartment.
Step-by-step explanation:
The effect the author achieves through the story's setting is multi-layered but primarily serves to create the story's central conflict and establish the mood. Randal's solitary presence in an empty apartment on a rainy day, reflecting on an absent person suggested by the empty cubbyhole, introduces a sense of loss or longing that contributes to the story's central conflict. The setting's details such as the relentless rain, the empty space, and Randal's inactivity while surrounded by these elements establish a melancholic and reflective mood.