The movie describes proletarian life in the Czech Lands after World War I.

The course of an organized strike by workers from North Moravian steelworks in 1931 to resist mass layoffs during the economic crisis.

The drama from the time of the Nazi occupation begins at the train station, where a transport with German soldiers is passing. The train is stopped due to improvised sabotage by one of the railway workers. Resistance liaison Růžena Kubínová is arrested in a random raid. The cynical councilor Dönnert discovers her false documents and has her brutally interrogated. He suspects that she could contribute to exposing the entire group. He puts a informant, Herta, in her cell.