The miller had always led a very prosperous life, but one day found himself down on his luck and without any money. While he is fretting, a nixy (a siren-like being) emerges from the mill-pond and strikes a deal with him - he can become prosperous once more, but he must give to her the youngest thing in his house. He agrees, thinking it will be a puppy or a kitten, but soon discovers his wife has just given birth to a son. Greatly despaired, he tells his wife of the bargain he has just made and they work hard to keep his son away from the mill-pond his whole life. After the son marries, he finds himself at the mill-pond one day and the nixy takes him. His wife then goes on a long mission to recover her husband.