The priest and the barber take their costumes and go with Sancho to seek Don Quixote and try to bring him home again. Sancho tells them the sage of all their adventures as they travel. When they reach their destination, Sancho moves on ahead, intending to make Don Quixote think he has seen Dulcinea, that he has handed her the letter, and that she wishes for Don Quixote to return home to her. It is agreed that if Don Quixote still will not come home, the priest and the barber will move forward with their scheme in which one pretends to be a damsel in distress who requires his assistance.
The priest and the barber wait for Sancho to return. They come across Cardenio, who relates the story to them. On this occasion, he includes the conclusion that he didn’t include when telling the tale to Don Quixote. Cardenio says that Ferdinand, while at Cardenio’s house, discovered a letter written by Lucinda and was so infatuated with her that he came up with a plan to win her himself. After sending Cardenio back to the Duke’s house, Ferdinand proposed to Lucinda. While still away, Cardenio got a letter from Lucinda asking him to come home. She explained that Ferdinand had proposed to her and that her greedy parents were insisting that she go ahead with the marriage. She was in a state of despair, feeling that she might kill herself soon. Cardenio gets home as quickly as he can, but only gets there in time to witness the wedding take place. Lucinda did not kill herself, instead resigning herself to accept Ferdinand in marriage. Cardenio hastened away from the wedding, venturing into the wilderness. He was mad with hatred and grief. Cervantes interrupts the narrative, stating that the conclusion of Cardenio’s story marks that of the third part of the history presented by Cide Hamete Benengeli.
Before the author returns to narration, Cervantes declares that the era in which Don Quixote lived was lucky that he revived knight-errantry. Once the story restarts, the barber, the priest, and Cardeno meet Dorothea, a young woman. At first they think she’s a man because she is dressed in men’s clothing. Dorothea conveys her tragic tale. Extraordinarily beautiful, she is the daughter of a wealthy farmer. The son of her father’s master began trying to woo her. She resisted his efforts until he one day came into her bedroom and swore that he would marry her. She gave into him because she feared he would rape her if she said no. He then left town, abandoning her. She chased him, hoping to force him to fulfill his promise to marry her but finding that he had already married another woman in another town. She explains that marriage’s circumstances, saying that the son who falsely promised to marry her was the Duke’s son, Ferdinand, and that Lucinda was his bride in the nearby town. Dorothea declares that after this her sense of shame forced her to run into the wilderness.
Cardenio is happy to discover from Dorothea that after Lucinda fainted, Ferdinand found a letter on her person revealing that she loved Cardenio. Cardenio promises to assist Dorothea in avenging what Ferdinand did to her. Dorothea suggests that she could take the part of the distressed damsel in the plot to trick Don Quixote to come home. Sancho comes back, bearing news that Don Quixote has refused to go to Dulcinea until he has gained honor by way of penance.
The priest informs Sancho that Dorothea is Princess Micomicona, who is hoping for Don Quixote’s assistance in redressing a wrong done to her by a giant. The costumed Dorothea, Sancho, and the barber, who is wearing a fake beard, find Don Quixote. Dorothea uses high poetic style when begging Don Quixote to kill a giant who has conquered her kingdom. Don Quixote promises that he will follow her and refrain from taking part in any other adventures as he makes his way. Sancho is satisfied, thinking now that he will get a governorship after all. Cardenio and the priest overtake the group on the road. Don Quixote is greeted by the priest, but he doesn’t recognize his old friend. He isn’t able to recognize Cardenio, either. The priest informs Don Quixote he and the barber were mugged by freed galley slaves.
Dorothea creates a story about the giant who she says attacked her kingdom. She makes mistakes a number of times during the story, and she even forgets the name given to her by the priest. The priest is forced to interject in order to stop her ploy being revealed. Dorothea declares that she will marry Don Quixote after the giant is vanquished, but Don Quixote says he is prevented from doing that by his love for Dulcinea. Sancho is upset by his refusal, and he insults Dulcinea. Don Quixote beats him in response. At this point, Gines de Pasamonte appears again, with Sancho’s donkey. He soon runs away. Dorothea and Cardenio talk about Don Quixote’s madness, and Cardenio says that Don Quixote is so insane he is certain no author exists who could have invented him.
Don Quixote begs Sancho to describe his visit to Dulcinea. Sancho invents a story, claiming that Dulcinea was at work and was unable to read the letter sent by Don Quixote. As they make their way along the road, the young body Don Quixote attempted to rescue from the beatings of his master in Chapter IV appears. The boy shows his disgust for Don Quixote’s stupidity in simply taking his master’s word and allowing him to get a worse beating. Don Quixote declares that he will take revenge on the boy’s master, but the boy says he doesn’t want Don Quixote to interfere again, worrying that it might only make the situation worse.