The film follows the life of a disillusioned and insomniac office worker desperate to escape the monotonous routine of his white-collar job. His search for meaning leads to chance encounters with a charismatic soap salesman and the formation of an underground fight club. The club is born out of a desire to experience something real amidst the numbing constraints of modern society. It starts as a form of primal therapy for men to release their frustrations through bare-knuckle brawling. The physical altercations serve as a cathartic release, and the club quickly gains popularity, spreading to multiple cities.

As the protagonist becomes more entrenched in the club's activities, he forms a complex relationship with the salesman and meets an enigmatic woman who complicates his life further. The fight club's ethos starts to evolve beyond the mere act of fighting, developing into a subversive subculture with its own anti-materialistic philosophy. This philosophy begins to spiral into something far more dangerous and anarchistic than the protagonist initially envisioned, threatening to upend not only his own sanity but also the very fabric of society. The questions of identity, purpose, and self-destruction become increasingly pertinent as he navigates the chaotic world he has become a part of.