"Mount," said the horse, "and let us be gone."
He mounted on the black horse, and away they went.
He reached the mountains, and he leaped the horse at the fire mountain and was on the top. From the mountain of fire he leaped to the mountain of ice, and from the mountain of ice to the mountain of snow. He put the mountains past him, and by morning he was in Realm Underwaves.
"You are come," said the prince.
"I am," said he.
"That's true," said Prince Underwaves. "A king's son are you, but a son of success am I. We shall have no more mistakes and delays, but a wedding this time."
"Go easy," said the Princess of the Greeks. "Your wedding is not so near as you think yet. Till you make a castle, I won't marry you. Not to your father's castle nor to your mother's will I go to dwell; but make me a castle for which your father's castle will not make washing water."
"You rider of the black horse, make that," said Prince Underwaves, "before the morrow's sun rises."
The lad went out to the horse and leaned his elbow on his neck and sighed, thinking that this castle never could be made for ever.
"There never came a turn in my road yet that is easier for me to pass than this," said the black horse.