Five teenagers from radically different social groups spend a Saturday morning in detention at their high school library. Over the course of the day, they learn lessons about each other and themselves. Claire (Molly Ringwald) is the spoiled princess, Andy (Emilio Estevez) is the popular jock, Brian (Anthony Michael Hall) is the brainy nerd, Allison (Ally Sheedy) is the misfit, and John Bender (Judd Nelson) is the juvenile delinquent with the heart of gold. The five form an unusual alliance against Principal Vernon (Paul Gleason) as they navigate the uneasy waters of high school social cliques and become friends through a series of shenanigans and heartfelt conversations.