But now again the sons of Usna had their home in their own eyrie. They knew not how long they might abide there in peace, for either the King of Alba, or Fergus of the Duns as his leader of men, would come again when once peace in the eastlands was secured. There Nathos wished to dwell alone with Darthool and a few followers, but Ailne and Ardan once more refused to leave him then or ever. But glad were the thrice fifty vassals to return to their own land, and without regret the sons of Usna saw them set sail for Erin. They were men who cared little for aught save strife, and when not wielding sword or spear were haughty and bitter with all other men save those of the Red Branch, and so were only a danger and a weariness in that place. Throughout that winter they lived there in peace, hunting and fishing. So great was the love of each for Darthool that every day was full of peace and content wherein they saw her. Nathos moved in a dream, and knew the extreme of joy. At night, before the fire, Darthool sang to them old-world airs of a sweet plaintive music, so sweet and plaintive that men said she must be no other than Fionula, she of the children of Lir who were turned into wild swans, and lived a thousand years in the old, old days. But when spring came again--a spring so fair and sweet that it was as though May had come hand in hand with February--a rumour reached them that the King of Alba, though he could not penetrate the highlands of the west, intended, with the help of Fergus of the Duns and other chieftains, to proceed once more against the Dun of Usna. Moreover, he had sworn to raze it to the ground, and to slay Nathos, and to take Darthool to be his wife. Nathos laughed at this, for he knew well that the King of Alba would never take him alive, nor yet Darthool. But after long colloquy with Ailne and Ardan, all decided to set forth and pass northward to the land whence their mother had come, a land of endless mountains and narrow lochs, beautiful beyond any other, grander than any Darthool had seen, and remote beyond the reach of any Alban king. So thither they set forth, and took with them in their great galley two score and ten men of their own clan. After long sailing up narrow lochs, the sons of Usna reached the mountain land whence their mother had come. Her father was dead, but the great dun he had built upon the summit of one of the hills overlooking the Black Loch had been left unharmed, and was tenanted only by wandering shepherds. Here Nathos and Darthool made their home, and in that beautiful land and in the glory of spring, knew the full joy and richness of life.[20] For a brief while all the people of the mountain lands round about gave in their adherence to Nathos, so that he became as a king in that region. So great was the fear in which the three sons of Usna were held, and so strong were they in their mountain home, that none dared to approach them with the flaming brand.