"Absolution" begins with Rudolph Miller’s visit to Father Schwartz’s room to reveal to the priest a terrible sin which Rudolph has committed and which is retold along with the events following it in a flashback. One Saturday afternoon Rudolph’s father, a devout Catholic, orders him to go to confession. In the confessional, Rudolph recites to Father Schwartz a list of minor sins, reflecting his romantic, imaginative nature as when he says that he believed he was too good to be the real son of his parents. He also tells the priest that he never lies, which is itself a lie. Rudolph does not realize this until his confession is nearly over and he is unable to confess this sin before the priest closes the confessional slat. Rather than feeling guilty, Ralph takes refuge,as at other times, in daydreams in which he is the debonair Blatchford Sarnemington.
With such a sin on his conscience, Rudolph must avoid going to communion the next day, so he resolves to drink a glass of water "accidentally" before going to church, since, under the Catholic law of the time, this prevents him from going to communion. Thus, early Sunday morning he sneaks into his kitchen to drink a glass of water and lend his story verisimilitude, when he is surprised by his father, Carl, just before he can put the glass to his lips. Seeing Rudolph about to disregard a religious injunction for no apparent reason, Carl verbally abuses his son and then beats him as punishment for defiantly throwing the glass into the sink. This is not an uncommon occurrence between the frustrated Carl and his willful son.
As they enter the church, Carl forces Rudolph to go to confession for his offense that morning, thus providing Rudolph with the opportunity to confess to lying so that he can go to communion with an easy conscience. Instead, Rudolph enters the confessional and lies a second time.
This deliberate violation of religious practice marks a turning point in Rudolph’s life: "The pressure of his environment had driven him into the lonely secret road of adolesence." A greater self-confidence enters him and he begins to recognize his own daydreams and ambitions. Ironically, Carl, seeing his son come back from confession, begins to regret his anger toward the boy. Rudolph receives communion with great trepidation and afterward believes that he is damned. Whereas the rest of the communicants are alone with God, Rudolph is alone with himself. He resolves to confess his sins to Father Schwartz the next day.
This brings the story back to its beginning: The reader now knows the events that Rudolph has been telling the priest. Father Schwartz, instead of giving conventional comfort or admonishing the boy, begins to speak in a strange fashion about parties and amusement parks and how "when a whole lot of people get together in the best places things go glimmering all the time." At first the priest’s chaotic mumblings frighten Rudolph, but then he realizes that Father Schwartz is simply expressing his own romantic, imaginative longings. Yet Father Schwartz also warns Rudolph not to become too closely involved with these beautiful things, "because if you do you’ll only feel the heat and the sweat and the life." Father Schwartz collapses under the strain of releasing his own feelings to the boy. Rudolph, terrified, runs out of the rectory with his sins absolved in a strange fashion.