Once upon a time, there was a king who had twelve daughters. Each one was more beautiful than the last.

The princesses all slept in the same room, in twelve beds set side by side. Every night, the king himself locked their door and kept the key.

But each morning, when the door was unlocked, the princesses' twelve pairs of shoes were worn through, as if they had been dancing all night long.

The king could not understand it. New shoes were brought every day. Every morning, they were ruined.

At last, the king made a proclamation. Whoever could discover where the princesses went each night would marry the daughter of his choice and inherit the kingdom. But anyone who tried and failed after three nights would be sent away in shame.

Many princes came. Each was given a fine bed in a small room beside the princesses' chamber, with the door left open so he could watch.

But every prince fell into a deep, strange sleep. And every morning, the shoes were worn through again. After three nights, each prince was sent away.

One day, an old soldier was traveling home from the wars. He met an old woman on the road who asked where he was going.

"I hardly know myself," he said with a laugh. "Perhaps I shall try to discover where the king's daughters dance their shoes through."

The old woman nodded. "That is not so hard," she said. "Only do not drink the wine they bring you. And take this."

She handed him a small cloak. "Whoever wears this becomes invisible. Then you may follow the princesses wherever they go."

The soldier thanked her. He went on to the palace and offered himself as a suitor.

That evening, he was given a fine room beside the princesses' chamber. As he prepared for bed, the eldest princess brought him a cup of wine.

The soldier pretended to drink. But he had tied a sponge under his chin, and the wine soaked into the sponge instead. Not a drop passed his lips.

He lay down and began to snore loudly, as though sound asleep.

The twelve princesses laughed. "Another fool," said the eldest. "He will sleep as deep as the rest."

They opened their wardrobes and put on the most beautiful dresses. They laced up new dancing shoes. They were full of joy and excitement.

Only the youngest princess seemed troubled. "Something feels wrong tonight," she whispered.

"You are always afraid," said the eldest. "Come along."

The eldest princess clapped her hands. The bed she stood beside sank into the floor, and a hidden staircase appeared, leading down into darkness.

One by one, the princesses went down the stairs. The soldier threw on his invisible cloak and followed.

On the way, he stepped a little too close to the youngest. She gave a cry. "Someone trod on my dress!"

"Don't be silly," said the eldest. "You caught it on a nail."

Down they went. At the bottom of the stairs was a forest where every leaf was made of silver. The trees shimmered in a soft, pale light.

The soldier broke off a small silver twig and slipped it into his coat — a gift to bring back as proof.

The youngest princess heard the snap. "What was that?" she whispered.

"It is only the trees stirring," said the eldest.

They came to a second forest where every leaf was made of gold. And then to a third, where every leaf was made of glittering diamonds. The soldier broke a twig from each.

At last, they reached the shore of a great lake. Twelve little boats waited there, with twelve handsome princes ready to row.

Each princess stepped into a boat with her prince. The soldier, still invisible, climbed in beside the youngest.

Her prince had to row very hard. "How heavy the boat is tonight," he said. "I am rowing with all my strength."

"It must be the warm weather," said the youngest. But her voice was uneasy.

Across the lake stood a great castle, shining with lights. From inside came the sound of trumpets and drums.

The princesses danced with their princes all through the night. They danced until their shoes were worn through.

When at last they grew tired, the princes rowed them back across the lake. The soldier slipped ahead and ran up the staircase before them.

He threw himself onto his bed and began to snore.

When the princesses came up, they laughed at the sleeping soldier. "Two more nights," said the eldest. "And then he will be sent away like all the rest."

The next two nights, the soldier did the same. He brought back a golden twig, then a diamond twig, hidden carefully in his coat.

On the morning of the fourth day, he was brought before the king.

"Have you discovered where my daughters dance each night?" asked the king.

"I have," said the soldier. He drew out the silver twig, the golden twig, and the diamond twig, and laid them on the table. "They go down a hidden staircase, through three forests, across a great lake, to a castle where they dance with twelve princes."

The princesses gasped. They knew their secret was discovered.

The king turned to the soldier. "You have done what no other could. Choose which of my daughters you will marry."

The soldier looked at them. "I am no longer young," he said. "Let me marry the eldest. She is closest to my own years."

And so the soldier married the eldest princess. The hidden staircase was sealed forever. And the twelve princesses never wore through their dancing shoes again.