"Aha!" cried Father Odin, well pleased at this offer. "And what reward do you ask, friend, for help so timely?"
The stranger hummed and hawed and pulled his long beard while he thought. Then he spoke suddenly, as if the idea had just come into his mind. "I will name my price, friends," he said; "a small price for so great a deed. I ask you to give me Freia for my wife, and those two sparkling jewels, the Sun and Moon."
At this demand the gods looked grave; for Freia was their dearest treasure. She was the most beautiful maid who ever lived, the light and life of heaven, and if she should leave Asgard, joy would go with her; while the Sun and Moon were the light and life of the Æsir's children, men, who lived in the little world below. But Loki the sly whispered that they would be safe enough if they made another condition on their part, so hard that the builder could not fulfill it. After thinking cautiously, he spoke for them all.
"Mighty man," quoth he, "we are willing to agree to your price—upon one condition. It is too long a time that you ask; we cannot wait three half-years for our castle; that is equal to three centuries when one is in a hurry. See that you finish the fort without help in one winter, one short winter, and you shall have fair Freia with the Sun and Moon. But if, on the first day of summer, one stone is wanting to the walls, or if any one has given you aid in the building, then your reward is lost, and you shall depart without payment." So spoke Loki, in the name of all the gods; but the plan was his own.
At first the stranger shook his head and frowned, saying that in so short a time no one unaided could complete the undertaking. At last he made another offer. "Let me have but my good horse to help me, and I will try," he urged. "Let me bring the useful Svadilföri with me to the task, and I will finish the work in one winter of short days, or lose my reward. Surely, you will not deny me this little help, from one four-footed friend."
Then again the Æsir consulted, and the wiser of them were doubtful whether it were best to accept the stranger's offer so strangely made. But again Loki urged them to accept. "Surely, there is no harm," he said. "Even with his old horse to help him, he cannot build the castle in the promised time. We shall gain a fortress without trouble and with never a price to pay."
Loki was so eager that, although the other Æsir did not like this crafty way of making bargains, they finally consented. Then in the presence of the heroes, with the Valkyries and Mimer's head for witnesses, the stranger and the Æsir gave solemn promise that the bargain should be kept.
On the first day of winter the strange builder began his work, and wondrous was the way he set about it. His strength seemed as the strength of a hundred men. As for his horse Svadilföri, he did more work by half than even the mighty builder. In the night he dragged the enormous rocks that were to be used in building the castle, rocks as big as mountains of the earth; while in the daytime the stranger piled them into place with his iron arms. The Æsir watched him with amazement; never was seen such strength in Asgard. Neither Tŷr the stout nor Thor the strong could match the power of the stranger. The gods began to look at one another uneasily. Who was this mighty one who had come among them, and what if after all he should win his reward? Freia trembled in her palace, and the Sun and Moon grew dim with fear.
Still the work went on, and the fort was piling higher and higher, by day and by night. There were but three days left before the end of winter, and already the building was so tall and so strong that it was safe from the attacks of any giant. The Æsir were delighted with their fine new castle; but their pride was dimmed by the fear that it must be paid for at all too costly a price. For only the gateway remained to be completed, and unless the stranger should fail to finish that in the next three days, they must give him Freia with the Sun and Moon.
The Æsir held a meeting upon Ida Plain, a meeting full of fear and anger. At last they realized what they had done; they had made a bargain with one of the giants, their enemies; and if he won the prize, it would mean sorrow and darkness in heaven and upon earth. "How did we happen to agree to so mad a bargain?" they asked one another. "Who suggested the wicked plan which bids fair to cost us all that we most cherish?" Then they remembered that it was Loki who had made the plan; it was he who had insisted that it be carried out and they blamed him for all the trouble.