It should be noted that while "Noon Wine" and its companion pieces, "Old Mortality" and "Pale Horse, Pale Rider," have been described as novellas, Ms Porter referred to them as short novels. Ms Porter, in the preface "Go Little Book . . " to "The Collected Stories of Katherine Anne Porter," abjured the word "novella," calling it a "slack, boneless, affected word that we do not need to describe anything." She went on to say "Please call my works by their right names: we have four that cover every division: short stories, long stories, short novels, novels."
Farmer "Royal Earle" Thompson runs a dairy farm in Southern Texas during the late 1890s. His farm is fairly unproductive due to his laziness and distaste for labor, which he considers "women's work." Thompson lives with his wife, Ellie, and his two young sons, Arthur and Herbert. Ellie is perpetually ill, though she does her best to perform her domestic duties around the house. The two boys are generally well-behaved, though rarely assist with the farm's chores, seeming to have inherited their father's laziness.
One day, the stranger Olaf Eric Helton arrives on the farm. The odd, pale Swedish man asks Farmer Thompson for a job. Thompson agrees to employ Helton, offering him a minuscule monthly salary, plus room and board. It is clear that Thompson views Helton as slightly less-than-human, due to his status as a foreigner. Helton proves himself to be an efficient farmhand, single-handedly transforming Thompson's run-down dairy farm into a productive, profitable enterprise. Thompson grows to appreciate and respect his mysterious Swedish farmhand, though he is unable to figure out anything about his personal life or origins, other than he came from North Dakota.
Nine years go by, and the Thompson dairy farm continues to thrive, thanks to Helton's incomparable work ethic. The Thompsons come to view Helton as one of the family, though they are puzzled by the fact that the Swede rarely speaks, never smiles, and constantly plays the same song on his precious harmonica. Ellie also recalls a bizarre event in which Helton silently shook her two boys in a terrifying manner after they had snatched his harmonica. She feels there is something strange about Helton, but decides not to mention the unsettling event to her husband, considering how much Helton has contributed to the family farm.
One day, the offensive and irritating Homer T. Hatch arrives at the farm. This new stranger annoys Farmer Thompson with his grating banter and subtle insults. Hatch eventually reveals the reason for his arrival. He claims to be a bounty hunter and that Olaf Helton is an escaped mental hospital patient who must be returned to the institution. Apparently, Helton went insane one day while farming, killing his only brother with a pitchfork. Thompson can't believe this information, and is reluctant to give up Helton to Hatch, whom he instinctively feels is an evil man.
At this point, Helton runs onto the scene, and Thompson witnesses Hatch drive a blade into Helton's stomach. Thompson rushes to Helton's defense, striking Hatch with an axe blade and killing him. Ellie witnesses the confrontation, and faints in the background. Helton flees the scene, but soon afterwards, he is captured where it is discovered he's completely unharmed. It appears Hatch's attack on Helton was a total hallucination in Thompson's mind.
After a perfunctory trial, Thompson is declared innocent on the grounds he was acting in self-defense, which is of course a lie. Yet despite the fortunate verdict, Thompson feels a horrible sense of guilt and is afraid the community will look down upon him. To clear his name, he decides to personally visit every member of the small farming community in an attempt to explain what happened. His efforts are unsuccessful, and the town begins to view him as dangerous and untrustworthy. Thompson, humiliated and realizing that even his wife is afraid of him, decides to commit suicide. He writes a note explaining why he killed Hatch, apologizing and saying "it had to be done." Thompson shoots himself with his shotgun.