After a heart attack, landowner Ferdinand Kerekházy summons his son Ferko Kerekházy from abroad, who, to his conservative father's dismay, sends a wagonload of machines ahead to set up an irrigation system and turn the saline, barely productive fields into fertile ones. The old count doesn't want to hear about his son's plans, and wants Ferko to marry Baroness Zólyomi. Since his son refuses, he disowns him. With persistent work, and the support of the mayor and a young engineer from Pest, the irrigation plan is realized. When the old count, who is always dreaming of grandchildren, realises that his son and the mayor's daughter have fallen in love, he reconciles with Ferko and asks her to marry him.