The story follows a man of "a noble descent" who calls himself William Wilson because, although denouncing his profligate past, he does not accept blame[dubious – discuss]for his actions, saying that "man was never thus [...] tempted before". After several paragraphs, the narration then segues into a description of Wilson's boyhood, which was spent in a school "in a misty-looking village of England". William meets another boy in his school who shared the same name, who had roughly the same appearance, and who was even born on exactly the same date (January 19, Poe's own birthday). William's name (he asserts that his actual name is only similar to "William Wilson") embarrasses him because it sounds "plebeian" or common, and he is irked that he must hear the name twice as much on account of the other William. The boy also dresses like William, walks like him, and even looks like him, but he could only speak in a whisper, he imitates that whisper exactly. He begins to give orders to William of an unspecified nature, which he refuses to obey, resenting the boy's "arrogance". One night he stole into the other William's bedroom and saw that the boy's face had suddenly become different. Upon seeing this, William left the academy immediately in horror, and in the same week, the other boy followed him. William eventually attends Eton and Oxford, gradually becoming more debauched and performing what he terms "mischief". For example, he stole from a man by cheating at cards. The other William appeared, his face covered, whispered a few words sufficient to alert others to William's behavior, and leaves with no others seeing his face. In his latest caper, he tries to seduce a married woman but the other William stops him at a ball in Rome; the enraged William drags his "unresisting" double—who was wearing identical clothes—into an antechamber, and stabs him fatally.
Cette nouvelle écrite à la première personne raconte la vie du narrateur qui choisit le pseudonyme de William Wilson. L'histoire commence dans la campagne anglaise, dans une école où le personnage particulièrement intelligent et manipulateur commence son éducation en compagnie d'autres écoliers. Un nouvel arrivant va bouleverser sa vie. Ce nouvel écolier porte le même nom que celui du narrateur et va calquer le comportement et les attitudes de ce dernier, son seul défaut étant qu'il ne peut élever la voix au-delà d'un chuchotement. De plus, il est le seul à rivaliser avec lui, contestant ainsi sa supériorité sur ses autres camarades. Le narrateur va s'en irriter jusqu'à quitter l'école pour poursuivre ses études à Oxford où il s'initie aux vices du jeu. Un soir, alors qu'au moyen de duperies il ruine un riche étudiant, un homme au visage couvert intervient et dénonce ses tricheries aux autres étudiants qui le prient de partir. Le narrateur fuit et poursuit son destin à travers l'Europe où son double intervient et met à bas ses plans.