On the way to Camelot, Pelleas meets Percival, who tells him about the affair between Lancelot and Guinevere, though refusing to malign the Queen. Pelleas later meets Lancelot and the two battle, with Lancelot proving himself stronger. They ride back to face the Queen, who realizes that Pelleas knows her secret shame. Modred knows the secret will soon become known to Arthur, saying "The time is hard at hand."
All of the knights seem to know the sin of Lancelot and Guinevere. Pelleas, newly knighted, at first upholds Guinevere as the ideal model for a wife:
Using Guinevere as the ideal wife, however, causes him to be ensnared by the beauty of Ettarre, who uses him and never loves him. He realizes "I never loved her, I but lusted for her." Ettarre is similar to Guinevere in that the Queen never loved Arthur. Pelleas, much like Arthur, remains faithful but is rejected by Ettarre. Instead, he finds Ettarre sleeping with a fellow knight whom he trusted. The episode, along with Percival's revelation of the affair, changes Pelleas' perception of the Queen; she is no longer his ideal. When he stands before her at the end of the ideal, she realizes that he too knows of her sin with Lancelot:
Guinevere, no longer viewed as a model wife, is hissed at and snakebitten by his response and by the thought that Arthur will soon find out the secret. She sees she is no longer respected as Queen, the affair having lower her in the estimation of the knights.