Two princes set out to seek adventure and fell into a wild life, never returning home. Their youngest brother, Simpleton, went to find them. When he did, his elder brothers mocked his simplicity. The three traveled together.
They came upon an anthill. The elder brothers wanted to destroy it, but Simpleton said, "Leave the creatures in peace." Later, at a lake with many ducks, the elder brothers wanted to catch some, but Simpleton again protected them. Finally, they found a beehive overflowing with honey. The elder brothers wanted to smoke out the bees, but Simpleton stopped them, saying, "Leave the creatures in peace."
They arrived at an enchanted castle with stone horses and no people. Deep inside, they found a door with three locks and a small window. Through it, they saw a little grey man at a table. They called three times before he rose, unlocked the door, and silently led them to a feast and then to bedrooms.
The next morning, the grey man led the eldest brother to a stone tablet inscribed with three tasks to break the castle's enchantment.
The first task was to collect a thousand pearls hidden in the forest moss before sunset, or be turned to stone. The eldest searched all day but found only a hundred pearls and was turned to stone. The next day, the second brother fared little better, finding only two hundred pearls and meeting the same fate.
When Simpleton's turn came, he struggled to find the pearls and wept in despair. The ant king, whose colony he had saved, arrived with five thousand ants. They quickly gathered all the pearls into a heap.
The second task was to retrieve the key to the princess's bedchamber from the lake. The ducks Simpleton had saved swam up, dove down, and brought him the key.
The third and most difficult task was to identify the youngest and dearest princess among three identical sleeping sisters. They could only be distinguished by what they had eaten before sleeping: the eldest ate sugar, the second ate syrup, and the youngest ate honey. The queen bee, whose hive Simpleton had protected, came and tasted each princess's lips. She settled on the mouth that had tasted honey, revealing the right princess.
The enchantment was broken. Everything awoke, and those turned to stone regained their forms. Simpleton married the youngest princess and became king after her father's death. His two brothers married the other sisters.