Lulu Massa (Gian Maria Volonte) operates a press machine in a factory, respected by his bosses but loathed by his coworkers, who consider him an overachiever. Lulu loses his finger in an accident, which changes his life and the factory at once. Lulu becomes involved in union activism, encouraging his colleagues to strike and losing his job. Lulu fights to be reinstated but wonders if it's worth the effort.
The Working Class Goes to Heaven immerses viewers in nine-to-five misery. Petri bombards viewers with whirring machines, shrieking alarm clocks and shouting workers, sweeping crane shots interrupted with sweaty close-ups, punctuated by a jolting, jackhammer-like Ennio Morricone score. Management encourages workers to maintain their work space as if it were an extension of themselves - something Lulu takes literally, when he compares himself to a machine. The imagery ranges from striking to silly, as when a newly-enlightened Lulu smashes a Scrooge McDuck doll.
Petri and screenwriter Ugo Pirro emphasize the situation's futility. Lulu's no happier rousing rabbles than making presses: his wife (Mariangela Melato) disapproves, his supervisors fire him, his coworkers think he's crazy. His allies are obnoxious student radicals who view him as a symbol rather than a person: he goes from corporate tool to socialist posterboy, capital and labor denying his humanity. His victory amounts to regaining his spot on the line, and dooming himself to a lifetime of misery.
Gian Maria Volonte makes Lulu confused and angry, lashing out at his wife and friends, struggling to reconcile his work ethic with humanity. Volonte delivers Lulu's diatribes with fevered indignation, while keeping the character shambling, awkward and uncomfortable in all settings. Mariangela Melato plays a vapid bourgeoisie, more concerned with wigs and TV shows than her husband's well-being. Salvo Randone plays an institutionalized coworker, whose "insanity" marks the logical extension of Lulu's predicament.
The Working Class Goes to Heaven isn't entirely satisfying, indulging in broad speechmaking and self-appraising irony. There's nonetheless a powerful jolt to its conclusion, with Lulu trying to relate a premonitory vision to his coworkers - but he can't recall anything more than fog behind an unbreakable wall, his message drowned by machinery.