The story's title character and narrator is a wealthy Englishman who shows an inclination towards wickedness from a young age. At boarding school, he meets another boy who is also named William Wilson. Apart from having the same name, there are also several other similarities between William Wilson and his namesake. William Wilson's namesake irritates him by giving him moral advice. For many years after he leaves boarding school, William Wilson finds that his namesake suddenly and mysteriously reappears whenever he attempts to commit a particularly wicked act.