The Pied Piper of Hamlin

How would you feel if someone breaks a promise to you? This German fairy tale cautions against breaking promises: When the town of Hamelin is plagued by a rate infestation, a mysterious piper appears to offer a solution to their problems. Elated, the mayor promises the piper a large amount of gold. However, after the piper successfully removed the rats, the mayor doesn't keep his words and refuses to pay. The town ends up paying a high price for the mayor's mistake...