When the feast was ended, and the company had departed, the king called unto him Fergus mac Roy, and said:—"Go thou, Fergus, and bring back the sons of Usna and their people. I promise thee that I will receive them as friends should be received, and that what awaits them here is not enmity or injury, but welcome and friendship. Take my message of peace and good will, and give thyself as pledge and surety for their safety. But these two things I charge thee to do:—That the moment you land in Ulaid on your way back, you proceed straight to Barach's house which stands on the sea cliff high over the landing place fronting Alban: and that whether the time of your arrival be by day or by night, thou see that the sons of Usna tarry not, but let them come hither direct to Emain, that they may not eat food in Erin till they eat of mine."
And Fergus, suspecting no evil design, promised to do as the king directed: for he was glad to be sent on this errand, being a fast friend to the sons of Usna.
Fergus set out straightway, bringing with him only his two sons, Illan the Fair and Buinni the Red, and his shield-bearer to carry his shield. And as soon as he had departed, Concobar sent for Barach and said to him:—
"Prepare a feast in thy house for Fergus: and when he visits thee returning with the sons of Usna, invite him to partake of it." And Barach thereupon departed for his home to do the bidding of the king and prepare the feast.
Now those heroes of old, on the day they received knighthood, were wont to make certain pledges which were to bind them for life, some binding themselves to one thing, some to another. And as they made the promises on the faith of their knighthood, with great vows, in presence of kings and nobles, they dared not violate them; no, not even if it was to save the lives of themselves and all their friends: for whosoever broke through his knighthood pledge was foully dishonoured for evermore. And one of Fergus's obligations was never to refuse an invitation to a banquet: a thing which was well known to King Concobar and to Barach.
As to Fergus mac Roy and his sons: they went on board their galley and put to sea, and made no delay till they reached the harbour nigh the campment of the sons of Usna. And coming ashore, Fergus gave the loud shout of a mighty man of chase. The sons of Usna were at that same hour in their booth; and Naisi and Deirdre were sitting with a polished chessboard between them playing a game.
And when they heard the shout, Naisi said:—"That is the call of a man from Erin."
"Not so," replied Deirdre, "it is the call of a man of Alban."
And after a little time when a second shout came, Naisi said:—"That of a certainty is the call of a man of Erin!"
But Deirdre again replied:—"No, indeed: it concerns us not: let us play our game."