Leaving Crúachan and mindful of Conor’s command, the three heroes rode on to the dún of Cu Roi in the far south west kingdom of Da Munhainn, each content with the secret they bore. Disappointed at Cu Roi’s absence, the warriors unyoked their tired horses and allowed themselves to be led into the round house by Blathnat, his woman who greeted them warmly preparing food and drink fit for heroes as well as comfortable beds for them to rest in. That night she told them that Cu Roi had left instructions that the warriors must mount night guard in order of their seniority and Laoghaire was deputised to go first, being the oldest of the trio.
As Laoghaire kept watch that night, he heard a distant rumbling and then from the west, where the sun had long since sunk, he saw a giant approaching, misshapen and huge, his head towering above the trees nearby and in the space between his legs Laoghaire cloud discern the far coastline. Stripped oaks, cut with a single stroke at their base, he threw at Laoghaire but they soared far over his head, landing Laoghaire knew not where. Hoisting his spear, Laoghaire stood up on the wall of the dun, prepared to sell his life dearly but the giant brushed his long spear aside and, reaching out grasped him in the palm of his hand. Mighty and stout though Laoghaire was, he fitted the giant’s hand as he could cradle a game piece within his own palm. With a jerk, the giant flipped him over the high wall of the dun so that he landed in the midden outside the dun.
The following night, the same sad events happened to Conall and he too was thrown over the wall of the dun.
When it was Cú Chulainn’s turn to guard the dun of Cu Roi, he went with an uneasy sense of foreboding and soon saw indistinct grey shapes in the night moving towards him and he called out. ‘I know not what you are. If you are friends, desist but if you are foe, beware.’
No sooner had he spoken that a group of nine dwarves launched an attack on him, hewing with short swords and daggers but Cú Chulainn sprang at them, slashing and hacking at them so that nine heads rolled on the ground, spouting blood. Alarmed by the booming sound, as if of a heavy sea was about to sweep over the dun, and standing up, Cú Chulainn saw that the incoming tide was flowing in over the land from the west and riding the surf was a hideous sea serpent of evil aspect. Rearing up, it opened its fearsome jaws as if in the act of swallowing man and dun in one gulp. Cú Chulainn, remembering the feats he had learned, swooped down upon the monster in a swallow dive as it neared the walls and clasped both arms around the monster’s slimy neck. Thrusting one arm down the serpent’s gullet he wrenched the beast’s slippery innards out, which he cast, with disgust, on the ground, before hacking the vile creature into bits with his sword.
Sitting there, exhausted and nauseated by the noxious fumes the serpent gave off, Cú Chulainn cursed when he saw, in the first glimmer of light from the east, striding in from the west, the giant Laoghaire and Conall had previously encountered.
‘You’ve had a hard night, by the looks of it,’ the giant commented wryly, looking at the heaped skulls of the dwarves and the scattered remains of the sea monster before the walls of the dun.
‘Well, you are not making it any better,’ Cú Chulainn snapped, springing to his feet and avoiding the giant’s lunge towards him.
Twisting around, Cú Chulainn made a salmon leap, vaulting over the giant’s head and onto his back, forcing his blade up and under the brute’s throat.
‘A life for a life,’ the giant panted.
‘Grant me three wishes, so,’ demanded Cú Chulainn.
‘Say what you will in the one breath and it will be so,’ the giant said.
Without stopping to think or to ease the pressure with which he held the blade to the giant’s throat, Cú Chulainn rapped out ‘The sovereignty of Eamhain Macha will be mine forever as will be the champion’s portion and the precedence of Emer over the ladies of the Ulaidh will last forever.’
‘And so it will be,’ claimed the giant before suddenly disappearing from Cú Chulainn’s grasp as the sun rose in the eastern sky. Blathnat found him sitting wearily on the guard step shortly afterwards.
‘Surely that is the tiredness of the valiant hero and not the exhaustion of the defeated. It is clear to me – and it would be also to Cu Roi, if he were here that the champion’s portion must go to Cú Chulainn for who else has amassed such a collection of spoils as this,’ she said, pointing to the cairn of heaped skulls and the foul carcase of the sea monster.
‘No, we cannot accept the word of a woman here,’ Laoghaire cried out contemptuously.
‘And lookit here to me,’ Conall pointed out, ‘this was the work of the Sídhe for how else can this serpent be explained as well as the mystery of the giant?’
‘As far as I am concerned,’ Cú Chulainn yawned, ‘I no longer care what anyone thinks of the champion’s portion for it seems to me the effort to get it outweighs the benefits if bestows.’
‘Well, if you cannot accept the judgement offered here, my lord Cu Roi planned for that and instructed me to order you back to Eamhain Macha where he will eventually arrive to pronounce final judgement.’