“William Wilson” is a tale narrated by an infamous criminal who is on the verge of death. He is ashamed to reveal his name; William Wilson is an admitted pseudonym. As death approaches, he tries to explain the momentous event that led to his life of misery and crime. His greatest fear is that he has forfeited heavenly bliss as well as earthly honor.

The path to the single event responsible for Wilson’s criminality begins in an ancient, dreamlike English village whose memories alone now afford him pleasure. The village includes the church and academy that Wilson attends from age ten to fifteen. Dr. Bransby, the pastor of the church, is also principal of the academy, and Wilson marvels at the “gigantic paradox” that allows one man to be both a benign clergyman and a stern disciplinarian. The academy is set apart from the mist-enclosed village by a ponderous wall and a spike-studded gate. Old and irregular, with endless windings and subdivisions, the school building becomes for the narrator a palace of enchantment. Even the low and dismal classroom is a source of spirit-stirring and passionate excitement.

At the academy, Wilson wins control over all of his fellows but one—a classmate with the same name as his. The two William Wilsons are identical in height and figure, move and walk in the same way, and dress alike. In fact, they were born on the same date and enter school at the same time. They seem to differ only in voice: The narrator speaks in normal tones, his namesake in a low whisper.

As time passes, their rivalry intensifies. They quarrel daily because of what the narrator calls his namesake’s “intolerable spirit of contradiction.” However, the narrator admits in retrospect that his rival was his superior in moral sense, if not in worldly wisdom, and that he would be a better and happier man today had he more often taken the advice given him.

Late one night, bent on a malicious joke, the narrator steals through narrow passages to his namesake’s room. There, as he looks into the sleeper’s face, he is overcome with such horror that he nearly swoons: The face he sees is identical to his own. Awestruck, the narrator flees to Eton College, where he soon dismisses what he has seen as an illusion. During an evening of prolonged debauchery, however, he encounters a shadowy figure who admonishes him with the whispered words “William Wilson” and then vanishes. This scene is reenacted at Oxford University. Just as the narrator’s cheating at cards brings Lord Glendinning, an aristocrat, to the brink of financial ruin, a stranger of the narrator’s height mysteriously appears. He points to evidence of the narrator’s cheating and, before disappearing, leaves behind a coat that is the duplicate of the narrator’s own.

The narrator leaves Oxford, but he flees in vain. In Paris and Berlin, in Vienna and Moscow, he is thwarted by the figure he now regards as his archenemy and evil genius. However, even as the narrator acknowledges his namesake’s elevated character and majestic wisdom, he vows to submit no longer. The confrontation occurs in Rome at the masquerade party of Duke Di Broglio, an aged Neapolitan nobleman. As the narrator threads his way through the crowd to seduce the young and beautiful wife of the duke, he feels a light hand on his shoulder, hears a low whisper in his ear, and sees a figure attired in a costume identical to his own. In a voice husky with rage, he orders the figure to follow him to an antechamber or be stabbed on the spot.

Inside the antechamber, they struggle briefly before Wilson repeatedly stabs his namesake through the bosom. However, it now seems as if there is a mirror in the room where none had been before, because Wilson sees his own image—spattered with blood—directly in front of him. Wilson soon realizes that what he sees is not a reflection; it is the blood-dabbled figure of his namesake. With his dying words, no longer in a whisper, the namesake says that Wilson has murdered himself and, in doing so, has lost all hope for happiness on earth or in Heaven.