Mysterious, manipulative, and utterly corrupt, Quilty is Humbert’s doppelgänger. He serves as a kind of mirror image of Humbert, reflecting similar traits and thoughts but embodying a darker side of those characteristics that Humbert stridently disavows. Quilty and Humbert both adore nymphets, but they act on their adoration in very different ways. While Humbert slavishly worships and idealizes Lolita, Quilty takes her for granted and wishes to denigrate her through pornography. Humbert paints himself as a man in love, while Quilty is, in many ways, a more typical pedophile. Both Quilty and Humbert are men of letters, well read and very persuasive, but Quilty has a much more successful career. Quilty is also far less subtle than Humbert about his nymphet obsession. Quilty’s professional success and reputation perhaps allow him to get away with his deviant behavior, though he is well known for his predilection for young girls and has already faced charges. At his final encounter with Humbert, Quilty’s baroque speech, cavalier attitude, and persistent game-playing imply that he, like Humbert, is not quite sane. He dies in the middle of an attempt to bribe Humbert with a variety of perverse pleasures.

Physically, Quilty appears infrequently in the novel, but his presence asserts itself through a relentless series of hidden clues. These clues, which include initials, place names, titles, and many other references and suggestions, build and intensify, creating a dense cloud above the actual story that eventually bursts when Lolita identifies Quilty as her lover. The clues reinforce the idea that Quilty is Humbert’s double, since he exists more as a shadow than as a living human being. That Lolita adores the intangible Quilty and remains unmoved by solid, present Humbert represents one of the novel’s crueler twists, and suggests that Lolita may indeed have had her eye on a future outside of Humbert’s control.