Once upon a time there was a king who had twelve beautiful daughters. The strange thing about them was that every morning their shoes were found to be worn off as if they had been dancing all night.
The king was puzzled and announced that whoever would find out where the princesses went every night could marry anyone of them. Many kings came to try their luck but they all failed to find the secret. An old soldier heard about this and decided to try his luck. He went to a sorceress, who gave him a cloak that would make him invisible. She also warned him not to drink the wine, which one of the princesses would bring for him.
Then the soldier went to the king. The king received him with full honour. At night, a feast was organised where the princesses served wine to him. He secretly threw away the wine and pretended to be asleep. The princesses, thinking that the soldier was asleep, went underground through a trap door. The soldier put on the cloak that would make him invisible and followed the princesses. He saw the princesses entering a beautiful garden.
Then, twelve princes came in twelve boats and took the princesses to a castle across the lake where they all danced the whole night till their shoes were worn. The soldier saw the same happenings three nights in a row.
On the fourth day, he told the king about the place where the princesses went every night. As proof, he showed one of the golden cups from which they drank wine. As his reward, he chose to marry the eldest princess.