Don Quixote and Sancho come to the river Ebro, where they find a fishing boat. Don Quixote takes the empty boat as a sign that he must use it to aid some imperiled knight. Much to Sancho’s dismay, they tether Rocinante and Dapple to a tree and set off in the boat. They do not go very far, but Don Quixote believes they have traveled two thousand miles. The boat reaches some mills, where Don Quixote and Sancho nearly perish. Some of the millers save them despite the curses of Don Quixote, who believes that the millers hold a trapped knight-errant in their mill, which he calls a castle. The fisherman who owns the boat arrives, and Don Quixote pays him off.
In the woods, Don Quixote and Sancho encounter a Duchess hunting with a Duke. Don Quixote sends Sancho to speak with the Duchess, and she receives him favorably, since she has read the First Part of the novel. She and the Duke resolve to treat Don Quixote according to the customs in books of chivalry. After initially falling off their respective mounts, Don Quixote and Sancho ride with the Duchess and the Duke to their castle.
Don Quixote, seeing that the Duke and Duchess are treating him according to chivalric traditions, feels certain that he is a true knight-errant. Sancho is also thrilled at their reception, but when he asks one of the maidservants, Doña Rodriguez, to care for Dapple, she refuses and they get into an argument. At dinner, the Duke forces Don Quixote to sit at the head of the table. Don Quixote and Sancho amuse the Duke and Duchess with their frivolity. The Duchess takes a particular liking to Sancho, who repeatedly embarrasses his master with his simplicity.
Don Quixote defends knight-errantry to a clergyman who condemns it as frivolity. The Duke promises Sancho that he will make him governor of some isle, and the clergyman storms out in anger. The servants play a trick on Don Quixote by washing his head in a basin and pretending to run out of water in the middle so that he must sit at the table with a mound of suds on his head. The Duke forces them to wash his head in the same way to maintain the ruse.
The Duchess asks Don Quixote to describe Dulcinea. He says he cannot remember what Dulcinea looks like, since her memory was blotted from his mind when he saw her transformed into an ugly peasant by enchantment. The Duchess challenges Don Quixote on the fine points of his love for Dulcinea and asks how he can compare Dulcinea to other princesses when he cannot even prove that she comes from noble lineage. Don Quixote answers that Dulcinea’s virtues raise her above her noble heritage. Meanwhile, Sancho goes off with the servants but comes running back in with several servants who want to clean him with dirty dishwater. Sancho implores the Duchess to intercede, which she does.
After dinner, the Duchess asks Sancho to accompany her to a cool place. Sancho agrees and, after making sure that the room contains no eavesdroppers, entertains her with stories of his adventures with Don Quixote. He tells her that he knows Don Quixote is crazy but that he stays with him out of loyalty. Sancho tells her how he deceived Don Quixote into believing in Dulcinea’s enchantment, but the Duchess convinces Sancho that he is the one who was actually deceived. She says that Dulcinea really was transformed into a peasant girl. Sancho tells the Duchess about his argument with her maidservant, Doña Rodriguez, and the Duchess vows to make sure that Dapple receives good care.
The Duke and Duchess go on a boar hunt with Sancho and Don Quixote. During the hunt, Sancho becomes afraid and attempts to climb a tree. The Duke tells Sancho that hunting helps to hone a governor’s skill for warfare, but Sancho maintains his distaste for the sport. Suddenly the woods fill with the sound of drumbeats and Moorish battle cries. The devil appears to announce the coming of Montesinos, who will give instructions to Don Quixote about how to disenchant Dulcinea. The noises continue and three wagons drive by. The wagons, which carry demons, are drawn by oxen with torches on their horns. Each of the wagons contains an enchanter who announces himself and then drives on.
An enormous wagon arrives carrying penitents dressed in white linen and a beautiful maiden with a golden veil. Merlin, bearing the face of death’s head, also rides on the wagon and addresses Don Quixote in verse, telling him that to disenchant Dulcinea, Sancho must whip himself 3,300 times on his bare buttocks and that he must do it willingly. This news distresses Sancho, who says that Dulcinea’s enchantment is not his problem. The maiden on the wagon, who pretends to be Dulcinea, chastises Sancho for his reluctance to come to her aid, and the Duke threatens to take away Sancho’s governorship if he does not comply. Sancho finally agrees but says that he will perform the whipping only when he feels like it. The scene pleases the Duke and the Duchess, who, it turns out, have arranged the whole trick in the first place.
The Duke and the Duchess indulge Don Quixote’s and Sancho’s fantasies, validating both Don Quixote’s belief that he is a grand knight-errant and Sancho’s belief that he will gain a governorship by being a good squire. Through all of their trickery they exhibit their willingness to engage Don Quixote’s madness. Don Quixote’s imagination does not need to do much work to transform his stay at the Duke’s castle into a magical one; it is the Duchess’s imagination, not his, that drives most of his adventures there. Furthermore, the Duchess’s indulgence of Sancho’s high opinion of himself gives Sancho a chance to express his philosophy about life, which turns out to be quite wise and deeply rooted in Christian ideals of charity. By playing along with Don Quixote and Sancho rather than mocking them outright, the Duke and Duchess gain Don Quixote’s and Sancho’s trust. This trust gives them power over Don Quixote and Sancho, which they abuse to stage their elaborate ruse.
Cervantes uses the encounter at the castle to continue his critique of his era’s conventional wisdom that social class corresponds to personal worth. Sancho is free to disagree with the lower-class Doña Rodriguez, but he is severely chastized by Don Quixote when he presumes to disagree with the Duke or the Duchess at dinner. According to the dictates of chivalry, Sancho, as a servant, may spar only with one of his own class. Likewise, Don Quixote treats the clergyman as roughly an equal, but he treats the Duke and the Duchess with the respect due to royalty. During their antics, the Duke and Duchess pretend that they are above everyone else, acting as puppeteers by stringing Don Quixote and Sancho along, tricking the men into believing each new fantasy simply for their own amusement. Though the Duchess does not appear overtly malicious, we see that she enjoys watching Sancho become more embroiled in Don Quixote’s madness. The pleasure she takes is a symptom of her tendency to look upon the peasant squire with condescension, which compels us to disdain her. The Duchess begins to appear cruel, since she enjoys keeping Sancho in a confused and vulnerable position, most notably when she tells him to believe in the enchantment of Dulcinea despite the fact that it is clearly fake.
In highlighting the Duchess’s awareness of the existence of the First Part of Don Quixote, Cervantes breaks down the wall between the work’s factual and fictional components. The Duchess has knowledge of Don Quixote’s past exploits, which shows that Cide Hamete Benengeli’s so-called historical account has influenced the events and people Don Quixote encounters. Notably, Don Quixote himself has not read the novel, which accounts for his failure to understand the perhaps good-natured mockery of those who have read it. In essence, he fails to see himself the way other characters within the story see him. Cervantes implies that if only Don Quixote would pick up the book and begin reading his own story, he might respond differently to those around him. Because they have read the story, the Duchess and other characters later in the Second Part can share a joke with us. The result is dramatic irony, since we are aware of the joke while Don Quixote himself is not. This irony draws us deeper into the novel, further blurring the line between madness and sanity, truth and lies.