The newlyweds lavish favors on Don Quixote for defending them and for his wisdom. Basilio admits it was he who had formulated the plan. Don Quixote says that to support the marriage of lovers is to honor virtue, for the enemy of love is caused by want.
Don Quixote does advise Basilio to find a better livelihood. A poor husband with a beautiful wife will have many trials—for many men will lust after her. A faithtful woman who withstands these trials is a jewel. A man should judge a woman by reputation than by wealth. A bad woman cannot mend her ways, but a good woman will improve.
Sancho mumbles to himself about how Quixote tells Sancho he should be at the pulpit, and yet Quixote is always eager to spout his wisdom. Quixote overhears him and asks what he is muttering about. Sancho says he wishes Quixote had advised him before he married—for Teresa is not as good as he would have her be. Quixote admonishes him for speaking ill of the mother of his children. Sancho says Teresa freely abuses him with her tongue, particularly when she is jealous.
They remain three days with the couple. The licentiate’s cousin arrives and agrees to give them a tour of the Cave of Montesinos and other sites Quixote wants to see.
Quixote asks about what the cousin does, and he claims he prints books. He describes several titles and what they are about. Sancho is impressed and asks him who is the first man that scratched his head. The cousin agrees with Sancho's theory that it was Adam. Sancho then asks who was the first tumbler, and the cousin admits he doesn't know--but if he ever finds out, he will let Sancho know. Sancho reveals he already knows the answer--it was Lucifer. The cousin agrees this is probably correct, but Quixote accuses Sancho of parroting someone else's ideas.
When they arrive at the Cave of Montesinos, Quixote hacks at the foliage obstructing the opening, disturbing the birds. He has the other two men lower him into the cave.
A half hour later, they pull him up. He is unconscious. When he comes to, he laments being woken from a wonderful vision. He is very hungry and asks for food.