The moaning Orchaoin made so great and terrible a voice that it was heard afar off. The Three Ceaseless Waves of Erin heard it, and roared responsive, so that all the coasts shook with their thunder: the Wave of Toth (Tuaithe), the Wave of Clidna (Cliodhna), and the Wave of Rudhraya (Rudhraighe). There was a great dun on these coasts, named Dun Tobairce, and there Conall Cernach the son of Amergin lived: and when he heard the roaring of the Three Waves of Erin, he knew that Concobar was in dire distress.
And that moaning of Orchaoin brought Conall Cernach on his magic steed that could fly through the night. He had with him his great sword “Blue Blade,” and when he came to the place of the strife he moved swiftly up behind Illann the Fair, and plunged “Blue Blade” into the back, and through the heart, and out at the breast of the hero.
But when Conall Cernach heard from Illann’s own lips what he had done, he was filled with wrath and grief.
“Thy faithless summons shall avail nought,” he cried into the torchlit darkness where Concobar was; and with that he took his sword, and severed from its body the head of Fiacha the son of Concobar, and tossed it towards the king. Then, turning his back upon the host, he departed as he had come.
With the death of Illann the Fair, the Ultonians once more took heart. They surrounded the Red Branch fort, and again set red flames leaping against it.
Then Ardan came forth: laughing lightly, and with a proud joy.
The Ultonians saw then what it was to perish as mown grass. And when he had slain five times fifty, his arms grew weary.
“How many did Illann the Fair slay in that onslaught of his?” he asked.
“Thrice five score,” he was told.
So Ardan slew two score and ten more, and then another score, for it did not befit so great a hero to slay less than an Ultonian champion, noble as Illann the Fair was.