The Love Potion
- The love potion Yseut's mother crafted only lasts for three years. The depth of the love it produces enables the lovers to endure a life of hardship without weariness.
- Tristan is hunting a stag one day when the potion wears off. He immediately feels bad about all the sadness he has caused Mark, the knightly life he has lost, and the hardship Yseut endures.
- Tristan resolves to leave Yseut, returning her to Mark.
- The potion wears off on Yseut, too. She laments the queenly life she has lost, and she tells Tristan that she believes they have gone astray because of the potion.
- Tristan tells Yseut that if Mark believes that they have not committed adultery, he will continue to serve Mark. If not, he will go to Brittany or Dumfries but always remain at Yseut's service.
- Tristan remarks that he would not separate from Yseut if he believed there were a way for them to remain together, but he believes that because of him, Yseut does not have the good life she deserves. He asks for Yseut's advice.
- Yseut reminds Tristan that the hermit Ogrin had once told them to repent. She suggests they return to seek his advice, and Tristan agrees.