During the Second World War a big plant in Urals region gets an order from the State Defence Committee: to double the output of the tanks T-34 within 24 hours. All physical and emotional strength of all plant workers needs to be exerted to fulfill the plan. The workers labor heroism is revealed through the story of a hereditary worker's family. His shoulders are burdened not only with a physical job, but also with responsibility for his younger son, who runs to the front without permission, not understanding that his battle-front is right here, on the plant.