Then Finn and his people went in, and the king made them welcome, and he bade Finn to sit down in his own place, and they were given strong pleasant drinks, and the king sent for the rest of Finn's people and bade them welcome to the dun.
Then Finn told what it was brought him there, and that it was to ask help and advice against the grandson of Duibhne he was come.
"And you have a right to give me your help," he said, "for it was he that killed your father and your two brothers, and many of your best men along with them."
"That is true," said the king; "and I will give you my own two sons and a thousand men with each of them." Finn was glad when he heard that, and he and his men took leave of the king and of his household, and left wishes for life and health with them, and the king did the same by them.
And it was near Brugh na Boinne Finn and his people came to land, and Finn sent messengers to the house of Angus to give out a challenge of battle against Diarmuid, grandson of Duibhne.
"What should I do about this, Osgar?" said Diarmuid.
"We will both go out and make a stand against them, and we will not let a serving-man of them escape, but we will make an end of them all," said Osgar.
So they rose up on the morning of the morrow and they put their suits of battle on their comely bodies; and it would be a pity for those, be they many or few, that would meet those two men, and their anger on them. And they bound the rims of their shields together the way they would not be parted from one another in the right. And the sons of the King of Alban said that they themselves and their people would go first to meet them. So they came to shore, and made a rush to meet Diarmuid and Osgar. But the two fought so well that they beat them back and scattered them, and made a great slaughter, and put great terror on them, so that at the last there was not a man left to stand against them.
And after that, Finn went out again on the sea, and his people with him, and there is no word of them till they came to the Land of Promise where Finn's nurse was. And when she saw Finn coming she was very joyful before him. And Finn told her the whole story from beginning to end, and the cause of his quarrel with Diarmuid; and he said it was to ask an advice from her he was come, and that it was not possible to put him down by any strength of an army, unless enchantment would put him down. "I will go with you," said the old woman, "and I will do enchantment on him." Finn was very glad when he heard that, and he stopped there that night, and they set out for Ireland on the morrow.
And when they came to Brugh na Boinne, the nurse put a Druid mist around Finn and the Fianna, the way no one could know they were there. Now the day before that, Osgar had parted from Diarmuid, and Diarmuid was out hunting by himself. That was shown to the hag, and she took a drowned leaf having a hole in it, like the quern of a mill, and she rose with that by her enchantments on a blast of Druid wind over Diarmuid, and began to aim at him through the hole with deadly spears, till she had done him great harm, for all his arms and his clothing, and he could not make away he was so hard pressed. And every danger he was ever in was little beside that danger. And it is what he thought, that unless he could strike the old woman through the hole that was in the leaf, she would give him his death there and then. And he lay down on his back, and the Gae Dearg, the Red Spear, in his hand, and he made a great cast of the spear, that it went through the hole, and the hag fell dead on the spot. And he struck off her head and brought it back with him to Angus Og.