Margo Roth Spiegelman could be considered the antagonist in Paper Towns, by John Green. She is not a villainess but she is at the center of the conflict. The protagonist, Quentin, is smitten with her and has been since childhood when Margo was his best friend. Margo is the “it” girl in school: she is beautiful, popular, and is part of the in-crowd.
But, there is a mysterious side to her that she conceals. She likes folk music and poetry, which she does not reveal because that would tarnish her image. Instead, she runs away, on occasion, to fulfill her adventurous side, a trait that is well known to her friends. Margo blames others for their misguided perception of her personality until she finally runs away and does not want to be found; she longs to find a place to call her own where she can allow her true personality to emerge.