William Hundert (KEVIN KLINE) is a teacher who's tried to inspire his various students over the past 34 years to better themselves and aspire to do great things with their lives. A practitioner of using prominent if long dead historical figures to demonstrate his points, Hundert has been invited by one of his former students, Sedgewick Bell (JOEL GRETSCH), to a reunion of sorts with him and his fellow former classmates.
As Hundert prepares for the weekend's activities, he remembers back to when he first met Sedgewick (EMILE HIRSCH) back in 1976 at St. Benedicts Academy for Boys. Working for Headmaster Woodbridge (EDWARD HERRMANN) and with Charles Ellerby (ROB MORROW), Hundert easily casts his academic spell over the likes of students Martin Blythe (PAUL DANO), Deepak Mehta (RISHI MEHTA) and Louis Masoudi (JESSE EISENBERG). Things change, however, with Sedgewick's arrival.
The son of U.S. Senator Bell (HARRIS YULIN), the boy is a natural troublemaker and it's not long before he's breaking the rules and disrupting Hundert's class. After a meeting with the Senator somewhat puts the boy in his place, Hundert - who's apparently having a fling with his married colleague Elizabeth (EMBETH DAVIDTZ) - takes it upon himself to encourage Sedgewick to better himself.
He also gets him to participate in the prestigious Julius Caesar contest and it's not long before Hundert must chose the three finalists. Faced with a daunting choice of upholding or bending the rules to help Sedgewick, Hundert makes a choice that could haunt him and have repercussions for years to come.