Shakespeare dedicated his sonnets to a “Mr. W.H.” No one knows who this was — his identity has remained a mystery for 400 years. Most of the sonnets are addressed to a young man, and some seem to contain puns on the names “Will” and “Hughes” (for example, sonnet 20 refers to “a man in hue all hughes in his controlling”), so the 18th-century scholar Thomas Tyrwhitt suggested that the young man was named William Hughes. Oscar Wilde took this up in his 1889 short story “The Portrait of Mr. W.H.,” in which he imagines that Mr. W.H. was one Willie Hughes, “a wonderful boy-actor of great beauty” who played women’s roles in Shakespeare’s company. Unfortunately there’s no evidence that such a person actually existed, though Samuel Butler discovered a real-life William Hughes who served as cook on a ship called the Vanguard in 1634.

In Ulysses, Mr. Best calls Wilde’s the “most brilliant” of all theories to explain the mystery. That’s ironic, because Ulysses contains a mysterious character of its own.