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.