Alistair and Miles, both hailing from aristocratic backgrounds, embark on their first year at Oxford University. While Miles demonstrates a friendly and composed demeanor—willingly offering to swap rooms after Alistair's accommodation fails to meet his parents’ standards—Alistair showcases his insecurity with a haughty, cold-hearted nature. He soon entangles himself with Lauren, a student from a humble Northern background, further complicating his already tumultuous personality. Within the elite environment of Oxford, the two serve as tutorial partners, where Alistair’s blatant contempt for Miles becomes evident, particularly when confronted with Miles's inclination towards leftist politics.
The prestigious Riot Club, a notorious drinking society renowned for its hedonism and the belief that wealth can secure any desire, initiates its quest for new members to ensure its ranks of ten men remain filled, all of whom must come from private schools. Alistair receives an invitation from Harry, whom he befriended during their term, while Miles is invited by Hugo after a night out at the pub. Alistair finds a mentor in Harry, who introduces him to his Uncle Jeremy, a senior MP—an ambition Alistair shares. Following a grueling initiation, they successfully become members of the Riot Club.
Shunned from most establishments in the city, the club decides to hold its annual dinner at a country pub. Much to their surprise, both Alistair and Miles find themselves in attendance, although Alistair can hardly conceal his disdain for the gathering. As the dinner progresses, despite the landlord’s initial excitement over hosting an aristocratic party, the club’s wild behavior quickly irritates the other patrons, causing several to leave. Frustrated, Chris, the landlord, confronts them about their disruptive antics. The boys, rather than accepting responsibility, strike a deal to compensate for the damages to continue their raucous festivities.
As tensions rise, Harry's hired escort refuses to engage in group activities, leading Alistair to mischievously take Miles's phone and contact Lauren without his knowledge. When she arrives, shocked by their crude propositions, Lauren attempts to leave but faces harassment from one of the members. Miles, desperate to help, is held back by others, and Hugo steps in to allow her to exit safely.
As the evening unfolds, Miles grapples with feelings of despair over Lauren’s treatment, while Alistair becomes increasingly intoxicated, falling deeper into his cynical worldview. The situation spirals out of control, resulting in the group wreaking havoc in their surroundings. When Chris confronts them about their destructive behavior, Alistair hurls insults, eventually leading to a physical altercation that leaves Chris unconscious. In the aftermath, a frantic Miles calls for an ambulance, but the boys, prioritizing their club over individual accountability, refuse to speak on the matter.
Following the incident, the club decides that Miles—being the newest member—should shoulder the blame. After a failed attempt to apologize to Lauren, who rebuffs him, they learn that Chris's skin was found under Alistair's fingernails, leading to Alistair's arrest while the others escape consequences. Though Alistair is expelled from Oxford, devoid of any further charges for his peers, Miles faces pressure from the new president of the Riot Club, Guy Bellingfield, to rejoin, but ultimately chooses to leave the club behind, an act that is met with mockery.
In a meeting with Jeremy in London, he seeks to shield the Riot Club from future legal scrutiny and assures Alistair that even with his expulsion, he remains part of their circle. Initially resistant to Jeremy's assistance, Alistair's attitude shifts when offered a position in his office and a secure future. The narrative culminates with Alistair leaving the meeting with a sense of triumph, a smug smile illuminating his face as he strides down the street, embodying the very essence of privilege and impunity.
