In a mill, far from people, lives a miller with her daughter Vojtěška. There is no man's hand here, but behind the dam of the pond lives a waterman, who does not leave the miller without help in difficult times. When the mill is most busy, unexpected help appears - a young traveler. Yesterday Vojtěška claimed that such a person had not yet been born, so that she could only look at him with her eyes. But today, under the full moon, a reed sings to her, so it is no wonder that she cannot sleep...