When he was come back to Brittany, to Carhaix, it happened that Tristan, riding to the aid of Kaherdin his brother in arms, fell into ambush and was wounded by a poisoned spear; and many doctors came, but none could cure him of the ill. And Tristan weakened and paled, and his bones showed.
Then he knew that his life was going, and that he must die, and he had a desire to see once more Iseult the Fair, but he could not seek her, for the sea would have killed him in his weakness, and how could Iseult come to him? And sad, and suffering the poison, he awaited death.
He called Kaherdin secretly to tell him his pain, for they loved each other with a loyal love; and as he would have no one in the room save Kaherdin, nor even in the neighbouring rooms, Iseult of the White Hands began to wonder. She was afraid and wished to hear, and she came back and listened at the wall by Tristan's bed; and as she listened one of her maids kept watch for her.
Now, within, Tristan had gathered up his strength, and had half risen, leaning against the wall, and Kaherdin wept beside him. They wept their good comradeship, broken so soon, and their friendship: then Tristan told Kaherdin of his love for that other Iseult, and of the sorrow of his life.
"Fair friend and gentle," said Tristan, "I am in a foreign land where I have neither friend nor cousin, save you; and you alone in this place have given me comfort. My life is going, and I wish to see once more Iseult the Fair. Ah, did I but know of a messenger who would go to her! For now I know that she will come to me. Kaherdin, my brother in arms, I beg it of your friendship; try this thing for me, and if you carry my word, I will become your liege, and I will cherish you beyond all other men."
And as Kaherdin saw Tristan broken down, his heart reproached him and he said: "Fair comrade, do not weep; I will do what you desire, even if it were risk of death I would do it for you. Nor no distress nor anguish will let me from doing it according to my power. Give me the word you send, and I will make ready."
And Tristan answered: "Thank you, friend; this is my prayer: take this ring, it is a sign between her and me; and when you come to her land pass yourself at court for a merchant, and show her silk and stuffs, but make so that she sees the ring, for then she will find some ruse by which to speak to you in secret. Then tell her that my heart salutes her; tell her that she alone can bring me comfort; tell her that if she does not come I shall die. Tell her to remember our past time, and our great sorrows, and all the joy there was in our loyal and tender love. And tell her to remember that draught we drank together on the high seas. For we drank our death together. Tell her to remember the oath I swore to serve a single love, for I have kept that oath."