The film is a story of a young man coerced into undercover work for the police, in return for their dropping of charges against him. He is to befriend a leader of a gang of juvenile delinquents who plans big robbery of a jewelry store. The scheme works and the gang is caught in the act except the gang leader.

After getting a university degree, Marek Grzyb comes back to his village and does his best to convince the people to modernize.