There was once a father who had three sons. When they reached a certain age, he sent them out to look for wives. The stupidest son, Hansel, was out looking when he walked past a pond and heard a frog speaking.
"Where are you going?" the frog asked. "I'm looking for a wife," Hansel replied. "Marry me!" said the frog. Simple Hansel agreed, and then returned home.
The father was waiting for his sons. "You have each found a wife," he told them. "I will give this house to the one who brings home the most beautiful wife."
Hansel hurried back to the frog and announced, "I am going to take you home now."
This made the frog very happy. It gave Hansel three keys and told him, "Go to that castle over there. Open three rooms, and take whatever you want from each room.