Once upon a time, a certain King was hunting in a great forest, and he chased a wild beast so eagerly that none of his attendants could follow him. When evening drew near he stopped and looked around him, and then he saw that he had lost his way. He sought a way out, but could find none. Then he perceived an aged woman with a head which nodded perpetually, who came towards him, but she was a witch. “Good woman,” said he to her, “Can you not show me the way through the forest?”
“Oh, yes, Lord King,” she answered, “that I certainly can, but on one condition, and if you do not fulfil that, you will never get out of the forest, and will die of hunger in it.”
“What kind of condition is it?” asked the King.