The Franks are choosing a man among them to serve as ambassador to the Spanish king Marsli, who has apparently conceded vicory to Chiarlymaen and Christianity. It is a dangerous mission, and a delicate one. In the following passages, Gwenlwyd is chosen as the ambassador. The aspect that distinguishes this episode in Cân Rolant from renditions of it in other works is the authors' more explicit judgment upon and expression of characters' intentions. Note also that Gwenlwyd repeatedly predicts his own treachery.

[Chiarlymaen:] "And you, barons, choose one of your number who may be fit to bear the weight of a mission which is as great as that!" And then Rolant remembered that Gwenlwyd had disparaged excessively his speech. And he rose to say that he did not know of anyone who would be more suited to that than Gwenlwyd, his stepfather. And then every one of the Franks praised Rolant's speech unanimously, judging that there was no man better fitted than he for that mission.

[...]

"It is Rolant," said Gwenlwyd, "who began to assert this - of whom I have known for a long time that he did not wish my life to last long. I shall not love him, on my part, from now on, and, in the presence of all the host of France, I shall withdraw my trust from him which I have maintained toward him too long, and I shall renounce also the Twelve Peers who are supporting him in his ill will. And I say to them, in everyone's presence, that I shall not be a friend to them from now on. And this year will not completely go by before the vengeance of that evil judgment comes upon whoever judged it."

[...]

"...And many were lost because of Rolant's pride," he said, "and many again will be lost, if there is any life remaining to him. And he hates my existence; and he has been thinking about shortening my life span for a long time. And why, lord, do you concur in his pride? Why, lord, are you sending me, your brother-in-law through your sister, to fight with Marsli at Rolant's instigation, after Basin and Basil? You have a nephew, a sister's son, who is my progeny - his name is Bawtwin - and the signs of his youth show that he will be a good man in the future. I shall entrust him to your faithfulness to protect him from Rolant's preparing death for him, after his father." "Your heart is too weak," said Chiarlymaen, "and your mind too womanish. And it is not fitting for a man, because of love for a son, to turn to saying a thing as weak as that."

And Gwenlwyd was greatly saddened, and he became dejected about going to Marsli. He stripped his mantle from around his neck, and he remained in a purple garment to draw the gaze of everyone upon him because his beauty was so remarkable; and he turned to Rolant without sparing his honor, and chastised him discourteously and bitterly: "Proud Rolant," he said, "what madness is in you that provokes you incessantly? What evil spirit is disturbing your thinking and your mind that you delight in troubling others and in making them restless like yourself? You have detained the Franks for seven years without respite now in Spain and caused them to toil in constant warfare so that neither sleep nor time for eating could part the men from their toil with arms. Our lives and our blood are worthless to you; and until you can assuage your madness, you care neither which nor how many of the barons of France are killed. I was your stepfather, and I had fatherly love for you; and you were a stepson to me as your own speech proves. But if God grant that I come back - and you wish that I never would - I shall pay you back for that. If I am killed because of you, you will have many enemies for as long as you live." "Although one uses it to threaten, the sword does not kill," said Rolant, "unless one strikes with it. And he has lost his threats uselessly who carries them before him who is not moved by fear of them. Complete the mission which was assigned to you, which I am sad was entrusted to you, a man as fearful as you; for I would prefer it if King Chiarlymaen had entrusted [it] to me before anyone."

And at that he ordered that the king's command be noted in a letter, under seal. And when the king put that letter in Gwenlwyd's hand, it fell from his hand to the ground because of fear. And as he picked it up off the ground, his shame made him break into a sweat before those who were looking at him and wondering at his cowardice and telling him that they considered the fall of the letter to be a sign and prediction of evil, and they feared that it was an evil omen for the future. "My action will test that," said Gwenlwyd, "and I think," he said, "that it is not useless for you to be afraid."

[...]

[Gwenlwyd's friends:] "O fortunate and gifted prince, may you come back in health. Little did he love you who sent you on this journey. And Rolant, your stepson, did not wish any better for you when he chose you for a mission as perilous as this. It would be an advantage for him, however, if you come back without receiving any insult from the wicked king. You have sprung, noble prince, from such a lineage that Chiarlymaen will not be able to defend Rolant against it if you do not return safely with your duties [discharged]."