“One of These Days” opens with Aurelio Escovar, an unlicensed dentist, entering his practice at six o’clock in the morning. He is dressed simply, in a collarless striped shirt and suspenders. He takes a set of false teeth out of a case, arranges his dental instruments in order of size, and then begins to polish the teeth, pumping the dental drill with seeming mindlessness for approximately two hours. At eight in the morning, he takes a break and looks out the office window, noticing two buzzards on his neighbor’s roof and thinking that it will probably rain before lunchtime. His young son then shouts from the waiting room that the mayor has arrived and needs a tooth extracted. Aurelio tells his son to send the mayor away and explain that Aurelio is not in. He then continues to polish a gold tooth, ignoring the situation. Aurelio’s son says that the mayor can hear Aurelio, to which Aurelio responds “so much the better” after finishing his work on the tooth. Eventually, the mayor gives Aurelio’s son the message that the mayor will shoot Aurelio if he will not help with the tooth. Aurelio unhurriedly stops his work and opens one of his desk drawers, which contains a gun. With a hand on the drawer and in an unconcerned tone, he sends his son out to challenge the mayor to come and shoot him.

The mayor enters, and Aurelio sees that the mayor has been in a great deal of pain; he has several days’ worth of stubble on the swollen side of his face, and “the dentist saw many nights of desperation in his dull eyes.” Aurelio closes the desk drawer and instructs the mayor to sit. The mayor wishes him a good morning, which Aurelio returns only with “Morning.” The mayor, as he sits, notices how bare and poor the office is. He tenses but opens his mouth as Aurelio approaches. Aurelio looks inside his mouth and sees that the mayor has an abscessed wisdom tooth; because of the abscess, Aurelio says, the extraction will have to be performed without any anesthesia. The mayor looks Aurelio in the eyes and agrees. Aurelio boils his dental instruments to sterilize them in preparation for the extraction and moves a spittoon close to the mayor. He also washes his hands, never looking at the mayor, although the mayor watches him intently as he goes about preparing for the procedure.

Aurelio returns and begins the extraction. He takes a set of dental forceps and grasps the mayor’s tooth. As the mayor braces himself, Aurelio says, “Now you will pay for our twenty dead men.” Tears fill the mayor’s eyes as he feels his tooth being pulled and the bones crunching in his jaw, but he does not cry out in pain. He holds his breath until the tooth is out, and when the dentist shows him his tooth, it is difficult for the mayor to fathom how it caused him so much pain the previous nights. The mayor bends over a spittoon, unbuttons his tunic, and reaches for his handkerchief, but Aurelio gives him a clean cloth and tells him to dry his tears. Aurelio again washes his hands, and the mayor notices the crumbling ceiling and a spiderweb in the corner of the office. When he finishes washing up, Aurelio tells the mayor to go to bed and gargle with saltwater, and the mayor begins to leave without buttoning his tunic back up. The mayor asks Aurelio to send him the bill, and when Aurelio asks if he should send the bill to the town or the mayor personally, the mayor responds through the closed screen door, “It’s the same damn thing.”