Since his early days in business, Geoffrey Betton had cherished "secret literary yearnings." But having attained critical and commercial success, Betton discovers that success brings intrusions and breeds apathy and pettiness in his character.

Betton felt a "thrill [when] he . . . opened the first" letter that arrived after the publication of his first novel, Diadems and Faggots, and he remembers that feeling to this day. However, his opinion of fan mail has since changed. The first fan letter asked if he minded a stranger telling him what his book meant to her. He did not mind then, but "ye gods, he minded now!" At first, "the publicity had been sweet to him," but soon enough, "his success began to submerge him," and he came to feel as though he were drowning in the flood of letters. Getting up in the morning used to fill him with a "sensuous joy," but now he rises late and languidly, the spring gone from his step.

Moreover, the attainment of success has negatively altered his motivations as a writer. As the narrator notes, “it was the worst part of his plight that his first success had goaded him to the perpetration of this particular folly — that one of the incentives (hideous thought!) to his new work had been the desire to extend and perpetuate his popularity. And this very week the book was to come out, and the letters, the cursed letters, would begin again!” Lured by the promise of broadening his public appeal, Betton has both compromised his art and summoned further intrusion.

Despite Betton's initial gratitude when letters about his first novel stop coming—along with the attendant requests for appearances and signatures and performances—he writes another book, to be published just two years after Diadems and Faggots.

The narrator says that "the moment was at hand when its author might have counted on regaining the blessed shelter of oblivion—if only he had not written another book!" Betton even has to admit to himself that "one of the incentives [. . .] to his new work had been the desire to extend and perpetuate his popularity."

Moreover, when the letters about his second book, Abundance, begin to slow, Betton actually begins to forge letters from readers. He does not want his secretary, Vyse, an old friend and rival writer, to think that his popularity is waning. And when he starts receiving what he thinks are letters from careful, invested readers, Betton's assessment of himself is swayed accordingly. Ironically, he concludes that "it was ridiculous to try to do conscientious work if one’s self-esteem were at the mercy of popular judgments." However, it is the good opinions of these letter writers which has restored Betton's own faith in his second novel.

The narration of “Full Circle” is limited to Betton’s perspective, and so readers witness Betton’s changing thoughts and speculations about Vyse. As Betton sees both surges and lulls in his influx of letters, he wonders what Vyse might think of their contents. Later in the story, he wonders, too, whether Vyse is responsible for fabricating some of the correspondence. In his thoughts, Betton often projects his own insecurities and emotions onto Vyse. As the story approaches its conclusion, the falsehood of Betton’s projections becomes increasingly apparent.

Near the end of the story, Betton admits to Vyse, his secretary and former literary rival, that he forged fan letters purportedly from one Hester Macklin (and, it is implied, some others) to himself. He assumes that Vyse has been judging him, reading his fan letters and laughing behind his back. He accuses Vyse of figuring out...