Douglas has watched his grandmother clean, dress, and stuff chickens for her boarding house guests so many times that he imagines he can almost do it himself. He is quite interested in the sizes, shapes, and uses of a chicken's internal organs and wonders if he looks like they do inside. His life is merry until Mr. Koberman rents the upstairs room. One morning, Douglas observes Koberman through the multicolored glass window in the upstairs alcove and, for a moment, believes that he can see inside him. What he sees staggers his boyish imagination. When Koberman catches him spying, he gestures angrily at Douglas with his umbrella. Koberman obviously fears being observed through this glass, for he breaks the colored window and manages to blame Douglas for the accident. Later that day, after Koberman goes to his room, Douglas sneaks in, carrying with him bits and pieces of the broken window. He examines Koberman with a discerning eye. Then, with the same meticulous skill that his grandmother demonstrates with chickens, Douglas performs exploratory surgery on Koberman with a large kitchen knife. He discovers strange shaped and marvelously colored gelatin-like objects within Koberman's body, all of which he takes to grandmother for identification. Strangely enough, though, Koberman's death does not result from the removal of his "parts." Instead, it is the "stuffing" that Douglas uses, the six dollars and seventy cents worth of silver coins that he sews inside Koberman's chest that causes him to die.
Bradbury feels strongly that a writer is never able to write well about anything with which he is unfamiliar. He advocates writing from personal experience, and such is the case in "The Man Upstairs" because Bradbury considers this story a eulogy of sorts to his grandmother whose culinary skills were always a delight to him.
"The Man Upstairs" is another of Bradbury's macabre tales in which the normal world with all of its rules and behavioral patterns is confronted with a creature whose actions are antithetical to the norm. Bradbury's love of the carnival and his great delight in Halloween surely must have merged here to create Mr. Koberman. He is, indeed, not the normal kind of boarder at Grandmother's boarding house, but Douglas is the only one to realize this due to his childhood perceptiveness. Koberman refuses to use the table silverware, he carries nothing but copper pennies in his pockets, and his working hours are at night rather than in the day. Even the surgery that Douglas performs does not end Koberman's life, for just as in the deeply steeped tradition of vampire legends, Koberman dies from silver implanted in his chest.
The analogy between Grandma and her chickens and Douglas and the man upstairs adds a light touch of humor to this story and therefore prevents Douglas's surgical murder of the vampire-boarder from ever becoming heavy-handed horror, typical of many of the other stories in The October Country.