Dan Dunne (Ryan Gosling) is a young teacher at a shabby Brooklyn junior high school, who somehow finds the energy to inspire his 13 and 14-year-olds to examine everything from civil rights to the Civil War with a new enthusiasm. Rejecting the standard curriculum in favor of an edgier approach, Dan teaches his students how to think for themselves.
Though Dan is brilliant, dynamic, and in control in the classroom, he spends his time outside school on the edge of consciousness. His disappointments and disillusionment have led to a serious drug habit. He juggles his hangovers and his homework, keeping his lives separated, until one of his troubled students, Drey (Shareeka Epps), catches him getting high after school. An uncertain friendship between the two develops.