The Sea-Maiden who became a Sea-Swan
The Sea-Swan told the story to the pigeons of the rock, and the Boy Who Knew What the Birds said heard every word of it. I was once a Sea-Maiden, she said, and my name was Eevil, and I was known through all the Kingdoms that are Under-Wave for my beautiful hair—my long, beautiful, green hair. Something was in me that made me want to dance, and I used to rise up through the water, and dance on the shore of the island that is called Hathony.
Mananaun, as you, creatures, know, is Lord of the Sea, and what he commands in the Kingdoms-Under-Wave has to be. Now Mananaun made a promise to a King of an Earth-Kingdom, and the promise was that he would give this King whatever he asked for. The King died according to the ways of men, and his son, whose name was Branduv, came to rule him.
Branduv called Mananaun out of the sea, and he asked that he renew the promise he had made to his father. The Lord of the Sea did not want a promise to lapse because of the death of a man, and he renewed it to the man's son. Then Mananaun told him he would take him and show him the Kingdoms of the Sea and whatever he saw that he desired there would be given to him. He took him in his boat of glass "The Ocean Sweeper" to visit the Kingdoms of the Sea.