Lake Mummel, nestled in the dark fir forests, owes its mysterious name to the lake maidens also called “Mümmlein”. They dwell in its unfathomable depths in a magnificent, crystal castle. It is surrounded by splendid gardens where blood-red coral grows alongside fragrant water lilies. The Mümmlein are lovely, charming creatures of delicate, slender build and rosy beauty. Every night they rise to the surface of the dark waters, perform a sweet dance to the sound of instruments, or hurry with their spindles to the nearest houses in the valley.

Long ago, the mermaids often came down into the valley to the farmers and woodcutters, helping in the house and yard or watching the children when the women were working in the fields. They were there early in the morning. But as soon as night fell and the stars appeared in the sky, they all had to be back in the crystal castle at the bottom of the lake. This was their king's command. One of the beautiful mermaids fell in love with a young farmer's son from Seebach. When the village fair came around again in the valley, the mermaids came down to the inn where the dancing was taking place. The mermaid who loved the farmer's son danced one dance after another with her sweetheart. Far and wide, no girl was as beautiful as the mermaid and none could dance so gracefully and lightly.

As darkness fell, all the maidens from the lake returned to their crystal castle. Only the one mermaid, who had her sweetheart in the village, couldn't bear to part from him. She wanted to dance just one more time. She thought that night fell earlier down in the valley than up in the forest. But she danced another round and another. And time passed, she didn't know how quickly.

Suddenly the clock struck ten on the tower. Now the mermaid realized her recklessness. Her heart grew anxious. And she drew her beloved from the hall into the open air. Silently, she hurried with him up the mountain forest. When they came to the lake, she spoke in a sorrowful voice: “Now we will probably never see each other again, for I must die. Wait a while longer on the shore. If blood rises from the depths, then I have lost my life; if not, I will soon be with you again.” She took a willow switch and struck the water three times with it. Then it parted, and a marble-white staircase appeared, leading down into the crystal castle. Behind the mermaid, the water closed again. It was dark night, and not a wave stirred. Then a small, dark wave rose from the depths of the lake. It was the blood of the poor mermaid, who had to die for his love.