A factory producing agricultural machines is about to be thoroughly modernized. If he wants to keep his job, master craftsman Kroupa (Jirí Sovák) is going to have to improve his qualifications through further training and completing his school-leaving exams. Kroupa is persuaded to go back to school by his subordinates who fear that the unbearable Hujer (Václav Lohniský), who has already signed on for schooling, may get promoted and take Kroupa's place. The students at the evening classes of the technical college are all middle-aged people. Even so, there are go-getters, shirkers and slobs among them just like in any other school.