This section is from the book "Myths And Folk-Tales Of The Russians, Western Slavs, And Magyars", by Jeremiah Curtin. Also available from Amazon: Myths and Folk-Tales of the Russians, Western Slavs, and the Magyars.
Thereupon they mounted their steeds, and set out for the realms of the old king. They went on easily till they reached the glass mountain, where the Hero of the Plain stopped, and said: "My dear younger brother, I cannot go on, for the diamond nails are long since worn from my horse's shoes, and his feet have no grip".
Mirko called to mind that the cursed old witch had given him the diamond nails, and said: "Grieve not, elder brother, I have nails; I 'll shoe thy horse this minute".
So he took out the nails, and shod the Hero's horse. Then they continued their journey over the glass mountain with ease and comfort, like two jolly comrades, and sped homeward as swiftly as thought.
At that time the old king was sitting at the window of his palace next the rising sun, and lo! he beholds two horsemen riding towards him. Straightway he takes his field-glass, and sees that it is his trusty old comrade, the Hero of the Plain, together with his son Mirko. He runs out, and from the tower commands that a twelve-year old ox be killed; and when Mirko and the Hero arrive, the great feast is ready. He receives them with joy, kisses and embraces them; this time both his eyes are laughing. Then they sat down to the feast, ate and drank with gladness. Meanwhile the Hero of the Plain spoke of Mirko's doings, and among other things said to the old king: "Well, comrade, thy son Mirko will be a better hero than we were; he is already a gallant youth. Thou hast cause to rejoice in him.
"Indeed, I begin to be satisfied with him," said the king, "especially since he has brought thee. But I do not think he would venture yet to measure strength with Doghead".
Mirko heard the conversation, but said nothing. After dinner, however, he spoke to the Hero of the Plain apart, and inquired who Doghead was, and in what direction he lived. The Hero of the Plain told him that Doghead lived in the north, and was such a hero that his like was not under the sun.
Mirko made preparations for his journey, took provisions, and next day set out for Doghcad's.
According to his wont, he sat on his steed, held fast, and closed his eyes. The steed sped on, flying like the swift whirlwind. At length she stopped, struck the ground, and said to Mirko: "Open thy eyes! What dost thou see?"
"I see," said the prince, "a seven-story diamond castle, so bright that I can look on the sun, but not on it".
"Well, Doghead lives there; that is the royal castle".
Mirko sprang towards it, stopped right under the window, and called out in a loud voice: "Art thou here, Doghead? I have an account to settle with thee".
Doghead was not at home, but his daughter was, and such a beautiful princess that her like could not be found on the whole round of the earth. As she sat by the window embroidering, and heard the loud, piercing voice, she looked out so angrily with her wondrous black, beautiful eyes that Mirko and his horse were turned into stone in an instant from the flash. Then she thought: "Maybe this young man is a king's son." She went to look at him, was sorry she had turned him to stone so quickly, and approached, taking a golden rod, walked around the stone statue and struck it on all sides with the rod. The stone began to move, and in a moment Mirko and his horse stood alive before her. Then the maiden asked, "Who art thou, and on what journey?"
Mirko answered that he was a king's son, and had come to see Doghead's daughter.
The maiden was so displeased that she called out to her father very angrily; but presently she thought better of it, fell in love with Mirko, and led him up into the seven-story diamond palace, where she saw him with a good heart. During conversation at the table, Mirko confessed that he had come to try his strength with Doghead.
The maiden advised him not to do that, since there was no man on the round of the earth whom her father could not conquer. Seeing, however, that Mirko would not desist from his purpose, she took compassion on him, and told how her father might, perhaps, be overcome. "Go down," said she "into the seventh cellar of the castle. There thou wilt find an unsealed cask, in which my father keeps his strength. Here is a silver flask; fill it from the cask. Do not stop the flask, but keep it always hanging from thy neck uncorked; and when thy strength begins to fail, dip thy little finger in. Every time thou shalt do so, thy strength will be increased with the strength of five thousand men. Drink of the wine, for every drop contains the strength of five thousand men".
Mirko listened to her advice attentively, hung the flask upon his neck, went into the cellar, and found the wine. He took a good draught of it; then thinking that he had enough, and lest Doghead might make further use of the wine, he poured it all on the ground, to the last drop. There were six measures of wheat-flour in the cellar, which he sprinkled around to absorb the moisture. Having done this, he went up to Doghead's daughter, and declared that he was ready, and thanking her for the counsel, vowed to take her as wife for her kindness, and swore eternal fidelity.
The beautiful princess consented, making one condition, - that if Mirko should overcome her father, he would spare his life.
Mirko asked the maiden when her father might be expected to return, and from what quarter.
She answered that he was then in the realms of the setting sun, that he took delight in those regions, but would soon be home, for it was the hour of his coming. But it was easy to know it beforehand, for when he was forty miles distant, he was in the habit of hurling home a forty-hundred-pound club before him; and wherever it fell a fountain gushed out of the earth.
Mirko and the princess went on the balcony to wait for Doghead; all at once (the Lord save us!) the sky grew dark, and a forty-hundred pound club fell in the court-yard. A stream rushed out of the earth as if from a force-pump.