On Homecoming Weekend at the historic Mission College in Georgia, the passionate senior Vaughn "Dap" Dunlap, portrayed by Laurence Fishburne, spearheads a protest rally against the school's complicity in apartheid in South Africa. This peaceful demonstration, however, is interrupted by the fraternity Gamma Phi Gamma and their pledge class known as the Gammites. Among them is Julian "Big Brother Almighty" Eaves, played by Giancarlo Esposito, who is a former friend of Dap and openly disagrees with his activist stance. Tensions escalate into a clash between Dap and Julian, but their quarrel is halted by Student Government Association president Virgil Cloyd, played by Gregg Burge.
Inside the administration building, Board of Trustees Chairman "Cedar Cloud," portrayed by Art Evans, instructs College President Harold McPherson, played by Joe Seneca, to put an end to Dap's protests. Meanwhile, Julian provokes fellow pledge Darrell "Half-Pint" (played by Spike Lee), reminiscing about how Dap dropped out of pledging years prior.
As evening descends, Dap summons his activist friends—Grady (Bill Nunn), Monroe (James Bond III), Jordan (Branford Marsalis), Edge (Kadeem Hardison), and Booker T. (Eric A. Payne)—to join him in continuing the protest. Despite their agreement with Dap's cause, they express concerns about their future, wishing to graduate and secure good jobs. In a parallel narrative, tensions rise among the Gamma Rays, a women's auxiliary group led by Julian's girlfriend Jane Toussaint (Tisha Campbell), who clash with Dap's girlfriend Rachel Meadows (Kyme) and her friends over issues related to skin color and hair politics.
On Saturday, the homecoming festivities kick off, leading to a near-physical confrontation between Dap’s followers and the Gamma brothers during the parade. The big homecoming football game that follows results in a disappointing defeat for the Mission football team, after which Dap is summoned by Cloud and McPherson. They threaten him with expulsion if he does not cease his activism.
Later, Dap and his friends head to a local KFC, where they experience hostility from locals who resent their privileged college status. Upon returning to campus, Dap confronts Julian regarding Darrell's status as a pledge.
As Sunday arrives, during a step show put on by the Greeks, a performance by Dap and his friends erupts into a fight with the Gammas. Dap seeks out Rachel, facing humiliation from her dorm neighbors, but ultimately, the couple mends their relationship. Later, Half-Pint and the Gammites proudly complete their pledging, embracing their new identities as fraternity brothers. During the celebration with the Gamma Ray sorority, Julian grows irritated with Jane and pressures Half-Pint into a compromising situation as a final test. Though uncomfortable with Julian's demand, Jane insists on compliance. This leads to a confrontation where Julian accuses Jane of caring more for the fraternity than for him, resulting in their breakup.
In a moment of realization, Half-Pint boasts to Dap about his actions at Julian's behest. Disturbed by how his cousin has changed into an entitled Gamma, Dap rushes to the center of the campus quad. With the dawn breaking, he rings a large bell, awake the slumbering campus from the night’s excesses. A tearful Julian confronts Dap, who then breaks the fourth wall and earnestly implores the audience, > "Please, wake up."
