A king had twelve beautiful daughters who slept in twelve beds in one room. Every night, the king locked the door. But every morning, their shoes were completely worn out, as if they had been dancing all night. No one knew how it happened.
The king made a promise: "Anyone who finds the secret in three days can choose one daughter to be his wife and will become king. But if he fails, he will be put to death."
Many princes tried and failed because they fell asleep during the night. One day, an old, wounded soldier came to the city. On his way, he met an old woman. She told him, "Do not drink the wine the princesses give you. Instead, pretend to be asleep." She also gave him a magic cloak that made him invisible.
That evening, the soldier went to the palace. The eldest princess brought him a cup of wine, but he secretly poured it away. He lay down and began to snore loudly. The princesses laughed, thinking he was fast asleep. They dressed in beautiful clothes and got ready to go out.
The eldest princess clapped her hands, and her bed sank into the floor, revealing a secret trap-door. One by one, the sisters went down. The soldier put on his magic cloak and followed them. On the stairs, he accidentally stepped on the dress of the youngest sister. "Someone is pulling my dress!" she cried, but her sisters told her she was imagining things.
At the bottom, they walked through three wonderful forests. The first had leaves of silver, the second had leaves of gold, and the third had leaves of sparkling diamonds. The soldier broke a branch from each tree as evidence.
They reached a large lake where twelve handsome princes were waiting in boats. The soldier sat in the boat with the youngest princess. The prince rowing the boat said, "The boat feels very heavy tonight!"
On the other side of the lake was a bright castle. They went inside, and the princesses danced until three in the morning. When their shoes were worn out, the princes rowed them back. The soldier ran ahead and jumped into his bed before the sisters returned.
In the morning, the soldier said nothing. He followed them for two more nights. On the third night, he took a golden cup from the castle. When the king asked for the secret, the soldier showed him the three branches and the golden cup.
The king called his daughters, and they had to tell the truth. The king asked the soldier, "Which princess do you want to marry?"
"I am not young," the soldier said, "so I choose the eldest." They were married that day, and the soldier became the heir to the kingdom.