Franěk from the mill loves Anička, the daughter of a poor widow, but his father, a miserly miller, is against their marriage. Anička turns to God for help, and soon after, two mysterious poor pilgrims visit her...

An adventure story about three boys who are at summer camp and soon notice that very strange and unexpected things are happening near the camp. And like proper boys, they decide to get to the bottom of all these mysterious puzzles. After a series of adventures and comical misunderstandings, the story's dénouement reveals that the boys have helped expose smugglers who are bringing refugees from the East across the nearby border and robbing them of their meager resources.