A dog barked; deep down in the earth a dog barked; it was Garm, the hound with bloody mouth, barking in Gnipa's Cave. The Dwarfs who heard groaned before their doors of stone. The tree Ygdrassil moaned in all its branches. There was a rending noise as the Giants moved their ship; there was a trampling sound as the hosts of Muspelheim gathered their horses. But Jötunheim and Muspelheim and Hel waited tremblingly; it might be that Fenrir the Wolf might not burst the bonds wherewith the Gods had bound him. Without his being loosed the Gods might not be destroyed. And then was heard the rending of the rock as Fenrir broke loose. For the second time the Hound Garm barked in Gnipa's Cave. Then was heard the galloping of the horses of the riders of Muspelheim; then was heard the laughter of Loki; then was heard the blowing of Heimdall's horn; then was heard the opening of Valhalla's five hundred and forty doors, as eight hundred Champions made ready to pass through each door. Odin took council with Mimir's head. Up from the waters of the Well of Wisdom he drew it, and by the power of the runes he knew he made the head speak to him. Where best might the Æsir and the Vanir and the Einherjar, who were the Champions of Midgard, meet, and how best might they strive with the forces of Muspelheim and Jötunheim and Hel? The head of Mimir counseled Odin to meet them on Vigard Plain and to wage there such war that the powers of evil would be destroyed forever, even though his own world should be destroyed with them. The riders of Muspelheim reached Bifröst, the Rainbow Bridge. Now would they storm the City of the Gods and fill it with flame. But Bifröst broke under the weight of the riders of Muspelheim, and they came not to the City of the Gods. Jörmungand, the serpent that encircles the world, reared itself up from the sea. The waters flooded the lands, and the remnant of the world's inhabitants was swept away. That mighty flood floated Naglfar, the Ship of Nails that the Giants were so long building, and floated the ship of Hel also. With Hrymer the Giant steering it, Naglfar sailed against the Gods, with all the powers of Jötunheim aboard. And Loki steered the ship of Hel with the Wolf Fenrir upon it for the place of the last battle. Since Bifröst was broken, the Æsir and the Vanir, the Asyniur and the Vana, the Einherjar and the Valkyries rode downward to Vigard through the waters of Thund. Odin rode at the head of his Champions. His helmet was of gold and in his hand was his spear Gungnir. Thor and Tyr were in his company.