The story 'My Sister and the Spider' revolves around a sister who is terrified of a spider she believes is haunting her from a nightmare.
The sister's fear of the spider intensifies when she believes the spider from her nightmare is present in their room, triggering a sense of imminent danger.
Despite initial hesitation, the narrator decides not to kill the spider, believing it may sense their fear and feed on it.
The narrative keeps suspense alive as the story ends with the spider's return the next evening, leaving the reader wondering about the unresolved tension between the characters and the mysterious spider.