"Sigh of a king's son under spells!" said the horse; "mount and you shall get the silver cup. The people of the realm are gathered about the king to-night, for he has missed his daughter, and when you get to the palace go in and leave me without; they will have the cup there going round the company. Go in and sit in their midst. Say nothing, and seem to be as one of the people of the place. But when the cup comes round to you, take it under your oxter, and come out to me with it, and we'll go."
Away they went and they got to Greece, and he went into the palace and did as the black horse bade. He took the cup and came out and mounted, and before sunrise he was in the Realm Underwaves.
"You are come," said Prince Underwaves.
"I am come," said he.
"We had better get married now," said the prince to the Greek princess.
"Slowly and softly," said she. "I will not marry till I get the silver ring that my grandmother and my mother wore when they were wedded."
"You rider of the black horse," said the Prince Underwaves, "do that. Let's have that ring here to-morrow at sunrise."
The lad went to the black horse and put his elbow on his crest and told him how it was.
"There never was a matter set before me harder than this matter which has now been set in front of me," said the horse, "but there is no help for it at any rate. Mount me. There is a snow mountain and an ice mountain and a mountain of fire between us and the winning of that ring. It is right hard for us to pass them."
Thus they went as they were, and about a mile from the snow mountain they were in a bad case with cold. As they came near it the lad struck the horse, and with the bound he gave the black horse was on the top of the snow mountain; at the next bound he was on the top of the ice mountain; at the third bound he went through the mountain of fire. When he had passed the mountains the lad was dragging at the horse's neck, as though he were about to lose himself. He went on before him down to a town below.