The following version of this novel was used to create the guide: Heringer, Victor. The Love of Singular Men. New Directions, 2023.

The novel begins in the year of 1976, where a boy named Camilo spends his life living on a wealthy estate in the suburb of Queím with his mother, his father Pablo, his sister Joana, a maid named Paulina, and a local woman named Maria Aína, who serves as Camilo's unofficial guardian throughout his childhood. Camilo suffers from a physical disability, while Joana is regarded as vulnerable because she is a girl, and the two are therefore confined to the property throughout much of their early childhood. One day, Pablo returns from his work as a doctor for Brazil's military regime with a young boy named Cosme in tow, toward whom Camilo immediately assumes a jealousy and distrust. Cosme initially attempts to run away from the home, but after some time and tenderness from Maria Aína, he begins adjusting to his life in Queím, which thoroughly unnerves Camilo. Although Cosme insists that his family died in a plane crash when he was young, it becomes increasingly apparent that Cosme is likely the orphan of a political prisoner whom the military regime has tortured and killed.

One day, Camilo attacks Cosme after watching him receive tenderness from his mother, and the expression of violence toward Cosme allows Camilo to move past his jealousy and begin regarding Cosme not only as a friend but also as an object of romantic affection. Camilo's mother and Pablo, meanwhile, begin initiating divorce proceedings, and as Camilo's mother becomes more and more withdrawn, it begins to dawn on Camilo that his father has likely committed or at least played party to terrible acts of violence in the course of his work for the military junta. To escape the unpleasant atmosphere of the house, Camilo and Cosme increasingly begin to spend time in and around the neighborhood, which prompts Camilo to realize for the first time in his life that his family is significantly wealthier than the families in the surrounding area. In spite of these class dynamics, Camilo and Cosme become friends with a group of neighborhood boys including Iguatemi, Knots, and Tiziu, through whom Camilo becomes acquainted with a neighborhood man named Adriano, whom the narrator reveals will eventually become Cosme's killer. Meanwhile, decades later, Camilo returns to Queím, befriends a man named Grumá, and starts to seek out the company of a young boy named Renato, whom he knows is Adriano's grandson.

Camilo and Cosme begin spending more and more time with the neighborhood boys, but each of them is treated as something of an outsider—Cosme because of his background as an orphan, and Camilo because he cannot participate in soccer games due to his disability. One day, the group of boys meet behind the old slave quarters in the neighborhood and participate in mutual masturbation together, but refuse to discuss this after the fact. As Camilo's mother and Pablo separately reel from the emotional devastation of their divorce, their oversight of Camilo becomes increasingly lax, and he and Cosme begin pursuing a sexual relationship with one another without being detected. Meanwhile, in Camilo's later years, he succeeds in inviting Renato over to his house and begins initiating a close relationship with him. Eventually, Camilo offers for Renato to live with him full-time, and grows increasingly possessive and jealous whenever Renato fails to appear at Camilo's house at the anticipated time.

As Camilo and Cosme's romance deepens, it becomes increasingly evident to the other boys in the relationship that they are queer, sparking debate and anger about whether or not Camilo and Cosme should be accepted in their community. After the boys have a violent fight over this question, their anger about Camilo and Cosme's sexuality subsides, and they accept the two boys with little more than occasional teasing comments. One day, Adriano, who is in a relationship with Paulina, the family maid, walks in on Camilo and Cosme in the act of intercourse, and Camilo immediately senses that Adriano is furious about what he has discovered. Not long after, Adriano catches Cosme after school, rapes him repeatedly, and then kills him in cold blood. In his later years, Camilo finds himself contemplating Cosme's murder with increasing frequency, and briefly considers killing Renato as an act of retribution before Renato's innocence snaps Camilo out of this reverie and stalls him from committing an act of violence.

Following Cosme's death, the community in Queím declines to prosecute the murder, instead choosing to look the other way and pretend as though Cosme never existed. Camilo's parents each separately brush away the circumstances leading to Cosme's murder, and Camilo realizes that they felt as though Cosme was predestined to suffer because of his class background and his lack of parents. As Camilo settles into old age, his relationship with Renato becomes more stable and more official, with Grumá agreeing to serve as Renato's godfather. One night, while drinking, Camilo opens up to Grumá about his queerness and his childhood love of Cosme, which Grumá receives tolerantly but without much real understanding of what Camilo has been through. Eventually, Camilo asks Renato's mother if he can adopt him, to which she agrees; as the pair celebrate the holidays together, Camilo privately decides that he will not return Renato to his family even if he asks to go back.