A socio-psychological drama about economically motivated migration of inhabitants of the countryside to cities. Coupled with problems with assimilation in a large-scale industrial environment, lack of experience and low skills result in a tragedy.
Young unskilled worker Sieczka is killed in a mine. In his testimony during the trial held in order to establish the reasons of the tragedy, technician Łopot blames it on an unfortunate coincidence. He is acquitted, with old machine operator Bartoszek now becoming a potential suspect. Bartoszek is the father of Magda, who is in love in Łopot. Unable to come to terms with the fact that he has been falsely accused, he quits his job. Łopot is getting a hard time from his co-workers and decides to do the same thing. He goes to Sieczka's home village to look after his mother. Upon arriving there, he discovers that the farm is being liquidated. Łopot returns to Silesia and reveals the truth. It turns out that he was protecting the victim of the accident out of fear that if he was found guilty his mother would not get a compensation, as well as his colleague Zyga, whom he had trained for the job and who caused the accident. Łopot also decides to return to the mine.
