NM Semenov - Hero of Socialist Labor, driver of the roadheader at the Shchekino mine (near the city of Tula), innovator and rationalizer of production processes. NM Semenov at home, assembling a model of a coal harvester for his son; listening to music with his wife in the theater; in the face of the mine, he controls the shearer. NM Semenov speaks at a scientific and technical conference of the Tula Mechanical Institute. NM Semenov, on behalf of the design bureau, works in the mine on a new complex combine harvester "Tula", which is being tested in production conditions. Mine accident: groundwater breakthrough, miners are closing the gap. NM Semenov receives guests - miners, on the model of the combine he has assembled, he explains to the guests the possibility of its improvement.