Don Quixote and Sancho begin searching for Cardenio. Sancho cannot bear the silence, and he tells Quixote that if he will not converse with him when they travel through lonely places, then give him leave to return home to his wife and children. Don Quixote gives him permission to speak when he pleases as long as they are traveling through the mountains.
Sancho asks why Don Quixote felt the need to defend the queen in the fairy tale. Had he have been silent, Cardenio would have continued his story. Don Quixote says the queen was a high-minded, virtuous lady. The bone setter was a tutor and a physician, not a lover. The fact that Cardenio said it while he was of unsound mind proves that he didn’t know what he was talking about. Sancho states that was the very reason Quixote should have ignored it. His master tells him that knights have to defend the honor of women, particularly queens. He begs Sancho to trust that he knows the laws of chivalry and not to meddle.
Sancho asks if it is a rule of chivalry to chase after a madman who might do them more injury. Quixote admits he is also seeking an adventure. He wants to imitate Amadis of Gaul and do penance. Sancho asks why he needs to do penance when he hasn’t been rejected. Quixote says that it will give his penance more meaning because it isn’t necessary. He plans to send Sancho with a letter to Dulcinea. Whatever her answer is will depend on whether his penance will end or if he will go mad.
Sancho tells Quixote that he thinks his brain is cracked, particularly as his master keeps insisting that the basin is a magical helmet. Quixote says that knights often appear to be in a fantasy world because enchanters use their magic to trick the senses of other people so they don’t see the things knights do. The helmet was made to appear as an object nobody would care about. If they truly knew what it was, they would pursue it to obtain it.
Quixote chooses a spot for his penance. He turns Rocinante loose, and Sancho decides to take the horse on his errand. Quixote wants him to wait three days before departing so he can report to Dulcinea what he is doing. He tells Sancho he will tear his clothes off and bang his head against rocks. Sancho suggests that Quixote not do that, and he can always lie to Dulcinea. Quixote says he cannot lie. He must bang his head on the rocks.
Sancho asks Quixote to write the letter so he can speed him on his way. He wants to return quickly so he can end Quixote’s penance. Sancho wants his master to also write an order for the donkeys he promised him.
As Don Quixote talks about Dulcinea, Sancho realizes her true identity. He admires her as well, for she is a strong woman—very out-going. He expects that she’ll laugh at Quixote’s letter. In the letter, Quixote asks Duclinea to be his. If she refuses, he will end his life.
Sancho worries he won’t be able to find Quixote when he returns. Quixote tells him he will keep an eye out for Sancho on the tallest mountain and cut down some trees to mark the way. Sancho leaves with the letters.