Gods and Fighting Men, by Lady Gregory [1904], at sacred-texts.com
ARTHUR, son of the King of Britain, came one time to take service with Finn, and three times nine men along with him. And they went hunting one day on Beinn Edair, and Finn took his place on the Cairn of the Fianna between the hill and the sea, and Arthur took his stand between the hunt and the sea, the way the deer would not escape by swimming.
And while Arthur was there he took notice of three of Finn's hounds, Bran, and Sceolan and Adhnuall, and he made a plan in his mind to go away across the sea, himself and his three nines, bringing those three hounds along with him. So he did that, and he himself and his men brought away the hounds and crossed the sea, and the place where they landed was Inver Mara Gamiach on the coast of Britain. And after they landed, they went to the mountain of Lodan, son of Lir, to hunt on it.
And as to the Fianna, after their bunting was done they gathered together on the hill; and as the custom was, all Finn's hounds were counted. Three hundred full-grown hounds he had, and two hundred wheips; and it is what the poets used to say, that to be counting them was like counting the branches on a tree.
Now on this day when they were counted, Bran and Sceolan and Adhnuall were missing; and that was told to Finn. He bade his people to search again through the three battalions of the Fianna, but search as they would, the hounds were not to be found.
Then Finn sent for a long-shaped basin of pale-gold, and water in it, and he put his face in the water, and his hand over his face, and it was showed him what had happened, and he said: "The King of Britain's son has brought away the hounds. And let nine men be chosen out to follow after them," he said. So nine men were chosen out, Diarmuid, grandson of Duibhne; Goll, son of Morna; Oisin, son of Finn; Faolan, the friend of the hounds, son of a woman that had come over the sea to give her love to Finn; Ferdoman, son of Bodb Dearg; two sons of Finn, Raighne Wide Eye and Vainche the Crimson-Red; Glas, son of Enchered Bera, with Caoilte and Lugaidh's Son. And the nine put their helmets on their heads, and took their long spears in their hands, and they felt sure they were a match for any four hundred men from the east to the west of the world.
They set out then, till they came to the mountain of Lodan, son of Lir; and they were not long there till they heard talk of men that were hunting in that place.
Arthur of Britain and his people were sitting on a hunting mound just at that time, and the nine men of the Fianna made an attack on them and killed all of them but Arthur, that Goll, son of Morna, put his two arms about and saved from death. Then they turned to go back to Ireland, bringing Arthur with them, and the three hounds. And as they were going, Goll chanced to look around him and he saw a dark-grey horse, having a bridle with fittings of worked gold. And then he looked to the left and saw a bay mare that was not easy to get hold of, and it having a bridle of silver rings and a golden bit. And Goll took hold of the two, and he gave them into Oisin's hand, and he gave them onto Diarmuid.
They went back to Finn then, bringing his three hounds with them, and the King of Britain's son as a prisoner; and Arthur made bonds with Finn, and was his follower till he died.
And as to the horse and the mare, they gave them to Finn; and the mare bred eight times, at every birth eight foals, and it is of that seed came all the horses of the fair Fianna of the Gael, for they had used no horses up to that time.
And that was not the only time Finn was robbed of some of his hounds. For there was a daughter of Roman was woman-Druid to the Tuatha de Danaan, and she set her love on Finn. But Finn said, so long as there was another woman to be found in the world, he would not marry a witch. And one time, three times fifty of Finn's hounds passed by the hill where she was; and she breathed on the hounds and shut them up in the hill, and they never came out again. It was to spite Finn she did that, and the place got the name of Duma na Corn, the Mound of the Hounds.
And as to Adhnuall, one of the bounds Finn thought most of, and that was brought back from the King of Britain's son, this is the way he came to his death afterwards.
There was a great fight one time between the Fianna and Macoon, son of Macnia, at some place in the province of Leinster, and a great many of the Fianna were killed. And the hound Adhnuall went wandering northward from the battle and went astray; and three times he went round the whole of Ireland, and then he came back to the place of the battle, and to a hill where three young men of the Fianna that had fallen there were buried after their death, and three daughters of a King of Alban that had died for love of them. And when Adhnuall came to that hill, he gave three loud howls and he stretched himself out and died.