A new student, Allison Taylor, joins Lisa's class. She's aas intelligent and as talented a saxaphone player as Lisa. Vying for first chair in the band, each girl blows complicated riffs in an attempt to outplay the other. Lisa faints from the effort, and Allison is awarded first chair.

Meanwhile, Homer steals 100 pounds of sugar from an oveturned truck and tries to sell his booty door-to-door. His efforts, however, are futile , and Marge insists that he dispose of the sugar. Homer refuses, but nature intercedes: a sudden rainstorm soaks the mound of sugar, causing it to dissolve.

Lisa feels increasingly average around Allison. Her spirits rise when Bart offers to sabotage Allison's entry to the school's diorama contest, replacing her elaborate scene of Poe's "The Telltale Heart" with a box containg a cow's heart. However, Lisa feels guilty and uncovers Allison's original project. Surpirsingly, both girls lose to Ralph Wiggum, who receives the prize for his display of action figures. Lisa and Allison patch up their differences and become friends.