In a boys' grammar school set in Sheffield, 1983, students Crowther, Posner, Dakin, Timms, Akthar, Lockwood, Scripps, and Rudge are celebrating their record-breaking A-Level scores, fueling their aspirations to attend either Oxford or Cambridge. They are preparing for an important seventh-term entrance exam in History. The beloved General Studies teacher, affectionately known as Hector, works closely with Mrs. Lintott, the deputy head and their regular History teacher. The Headmaster, referred to as Felix, hires a new temporary teacher, Tom Irwin, who claims to have attended Jesus College, Oxford. However, during an interview, Dakin discovers that Irwin actually did not attend university there, only further deepening the intrigue surrounding his character.
As part of their unique General Studies curriculum, the boys enthusiastically participate in reenacting scenes from various romantic films and literature. Each class concludes with Hector offering a ride home to a student on his motorbike, which some rumors reveal may involve inappropriate touching, initially dismissed as mere gossip. Notably, Posner, a slight Jewish boy, harbors feelings for Dakin but is never chosen for the rides. Dakin, portraying an aspiring lecher, is entangled in a flirtation with the headmaster's secretary, Fiona, yet finds himself increasingly drawn to Irwin, leading to a complicated interplay of attraction and academia.
As their studies progress, Hector's indiscretions come to light, resulting in Felix's decision for him to "retire early." Despite this, all the boys secure places at prestigious institutions, with Posner earning a scholarship and Dakin attaining an exhibition, despite some ambiguity about their achievements. Upon receiving their results, Dakin confronts Irwin about his dishonesty regarding attending Oxford. In a surprising turn, Irwin admits his true educational background, which sets the stage for a more intimate invitation from Dakin for a drink, revealing his romantic intent towards Irwin—an invitation that leaves Irwin both confused and intrigued.
In a twist of fate, as the boys prepare to depart the school, Hector offers Dakin a nostalgic ride home on his motorcycle, only to be stopped by the Headmaster, who suggests that Hector should take Irwin instead. Dakin happily hands over the helmet, sealing a moment of anticipation that fades into white as they drive away, laughter and excitement accompanying them.
Tragically, an off-screen motorcycle accident claims Hector's life, with Irwin suffering a broken leg. Dakin reflects that Irwin, having never been a passenger on a bike, may have inadvertently contributed to the accident's dire consequences. The boys later honor Hector by singing "Bye Bye Blackbird" at his memorial, while Mrs. Lintott, observing the boys recount their futures, wonders about her own legacy. The film concludes with a poignant scene as Hector's voice encourages the boys to "pass it on," leaving viewers with a bittersweet message about mentoring and the passage of knowledge.
