An insightful, achingly funny coming-of-age story as well as a brilliant dissection of class, race, and gender in a hothouse of adolescent angst and ambition.

Lee Fiora is an intelligent, observant fourteen-year-old when her father drops her off in front of her dorm at the prestigious Ault School in Massachusetts. She leaves her animated, affectionate family in South Bend, Indiana, at least in part because of the boarding school’s glossy brochure, in which boys in sweaters chat in front of old brick buildings, girls in kilts hold lacrosse sticks on pristinely mown athletic fields, and everyone sings hymns in chapel.

As Lee soon learns, Ault is a cloistered world of jaded, attractive teenagers who spend summers on Nantucket and speak in their own clever shorthand. Both intimidated and fascinated by her classmates, Lee becomes a shrewd observer of—and, ultimately, a participant in—their rituals and mores. As a...