Set in Turin at the end of the 19th century, the film opens with a stark peek into the daily grind of textile workers. Among them is the young Omero Franco Ciolli, who rises at 5:30 in the morning to join a grueling long day that stretches until 8:30 in the evening, vividly illustrating the harsh rhythm of industrial labor. The atmosphere is crowded with ages and strains, yet the collective spirit of the workers remains, even as fatigue gnaws at their resolve.
As the day wears on, disaster strikes when the hand of a drowsy worker is mangled by a machine. In response, a small, determined committee forms—led by Pautasso [Folco Lulli], Martinetti [Bernard Blier], and Cesarina [Elvira Tonelli]—to press management for a real change: shorten the 14-hour workday to prevent more accidents. Their appeal is met with cold admonitions to be more careful, not with concessions, and the workers’ hope begins to flicker under the weight of quiet indifference.
Undeterred, the workers attempt to dramatize their grievances by staging a walkout an hour early the next evening, but fear and nerves override the plan, and they retreat to the familiar routine of the long day. It is at this tense moment that Professor Sinigaglia [Marcello Mastroianni], a labor activist on the run from the police in Genoa, hops off a freight train and slips into the neighborhood. He attends a meeting where the workers openly discuss coming in an hour late, and he injects them with a new, sharper resolve: they should escalate their struggle by not appearing at all and by mounting a full, sustained strike. He also guides them in practical preparations, helping them amass supplies and organize for a drawn-out fight.
The workers’ gratitude toward Sinigaglia earns him a place of trust, as they appoint him as a guest to Raoul [Renato Salvatori], a seasoned but skeptical colleague who doubts the odds of their collective action and resents the arrangement. This uneasy alliance injects a human tension into the unfolding drama: can idealism born in a moment survive the harsh calculations of real-world labor?
When management throws a curveball—token concessions without reducing the hours—the plan backfires and replacement workers are brought in from another factory to take over. A violent clash ensues between the strikers and these newly hired workers, and Pautasso is killed in the confrontation. The incident triggers press attention and government scrutiny, forcing the factory owners to recall the replacements. Yet the authorities also close in on Sinigaglia, forcing him to move once more as he evades capture.
As the strike drags on into a second month, the factory owners suffer heavy financial losses and inch toward compromise, but the workers, running low on supplies and morale, are uncertain. Then Sinigaglia reappears and delivers a rousing, uncompromising plea: keep striking and raise the stakes by occupying the factory itself. The mood shifts from protest to confrontation, and a tense showdown unfolds between the strikers and an army unit pinned at the gates. Gunfire erupts, Omero is killed, and the crowd scatters in panic. Sinigaglia is arrested, and Raoul, in a burst of defiance, attacks a police officer and must go into hiding once more.
The conclusion circles back to the grim stage it began on: the factory gates reopen, and the workers return to the grind, their faces set in hard resolve. Omero is replaced by his younger brother, whom Omero had hoped would seize a chance at a different life through education, but the fate of factory work lingers. Raoul boards a freight train and escapes to seek shelter with a fellow member of the underground labor movement in another city, now more determined than ever to push the struggle forward. The film leaves a stark impression of endurance, solidarity, and the costs of collective action, underscoring how the fight for better conditions threads through generations of workers.
