Dismissed from the railroads in 1863 for his union activities, Etienne Lantier found a job at the Voreux coal mine. But work was hard, wages were low and safety left much to be desired. Lantier tried to organize the miners into a union. When mine manager Hennebeau refused to negotiate, the workers launched a general strike, which ended with the intervention of the troops.
In a rural scenery in the throes of difficult changes lives a humble but promising young farmer girl called Mari Pataki. Her father forbids her from seeing the man she loves. The father, above all preoccupied by work on the fields and prospective wealth, decides to give his daughter in marriage to an old but rich man with whom he does business. Land marries land, he says. This seems to be the unyielding rule of the Hungarian peasantry. But the young lover is ready to stand up to any challenge to keep Maris love.