He could do no more.

The axe fell from his grasp, and he reeled back.
As he did so there rose, loud above the wind and above the howling of the wolves, a cry which caused Sigurd to start once more to his feet, and the wild beasts to pause midway in their mortal onslaught.
It was the deep-mouthed voice of a dog, and next moment a huge mastiff dashed from out of the thicket and fastened on the throat of the foremost wolf.
It was Sigurd's own watch-dog Thor, whom some dear hand had loosed from his chain and sent forth into the forest to guard and maybe save his master.
At the sight of the great champion, and at sound of his bark, the cowardly wolves one by one slunk sullenly back into the woods, and Sigurd felt that he was saved.
A joyous meeting was that between gallant master and gallant hound.
"Thor, my brave dog," cried Sigurd, "is it to thee, then, I owe my life--my brother's life?
Yet not to thee so much as to the fair lady who sent thee, a messenger of love and life to me.

Thanks, Thor, thanks lady, thank most to God.

Now shall I reach Niflheim even yet." Thor wagged his great tail and barked joyfully in answer.
All that night Sigurd lay secure, watched over by the sleepless Thor, whose honest bark was the sweetest music that ever lulled a hero to repose.
For two days Sigurd trudged safely onward through that dense forest, with Thor, the dog, beside him.

The way was hard and painful, and the hero's limbs, now his only support, crashed wearily through the thickets.