In this extraordinary way the noble city of Asgard was made safe and complete by the addition of a fortress which no one, not even the giant who built it, could injure, it was so wonder-strong. But always at the top of the gate were lacking three great stones that no one was mighty enough to lift. This was a reminder to the Æsir that now they had the race of giants for their everlasting enemies. And though Loki's trick had saved them Freia, and for the world the Sun and Moon, it was the beginning of trouble in Asgard which lasted as long as Loki lived to make mischief with his guile. THE MAGIC APPLES It is not very amusing to be a king. Father Odin often grew tired of sitting all day long upon his golden throne in Valhalla above the heavens. He wearied of welcoming the new heroes whom the Valkyries brought him from wars upon the earth, and of watching the old heroes fight their daily deathless battles. He wearied of his wise ravens, and the constant gossip which they brought him from the four corners of the world; and he longed to escape from every one who knew him to some place where he could pass for a mere stranger, instead of the great king of the Æsir, the mightiest being in the whole universe, of whom every one was afraid. Sometimes he longed so much that he could not bear it. Then--he would run away. He disguised himself as a tall old man, with white hair and a long gray beard. Around his shoulders he threw a huge blue cloak, that covered him from top to toe, and over his face he pulled a big slouch hat, to hide his eyes. For his eyes Odin could not change--no magician has ever learned how to do that. One was empty; he had given the eye to the giant Mimer in exchange for wisdom. Usually Odin loved to go upon these wanderings alone; for an adventure is a double adventure when one meets it single-handed. It was a fine game for Odin to see how near he could come to danger without feeling the grip of its teeth. But sometimes, when he wanted company, he would whisper to his two brothers, Hœnir and red Loki. They three would creep out of the palace by the back way; and, with a finger on the lip to Heimdal, the watchman, would silently steal over the rainbow bridge which led from Asgard into the places of men and dwarfs and giants. Wonderful adventures they had, these three, with Loki to help make things happen. Loki was a sly, mischievous fellow, full of his pranks and his capers, not always kindly ones. But he was clever, as well as malicious; and when he had pushed folk into trouble, he could often help them out again, as safe as ever. He could be the jolliest of companions when he chose, and Odin liked his merriment and his witty talk.