After a few adventures together, Don Quixote and Sancho Panza discover a bag full of gold coins along with some papers, which include a sonnet describing the poet's romantic troubles. Quixote and Sancho search for the person to whom the gold and the papers belong. They identify the owner as Cardenio, a madman living in the mountains.
Cardenio begins to tell his story to Quixote and Sancho: Cardenio had been deeply in love with Luscinda, but her father refused to let the two marry. Cardenio had then been called to service by Duke Ricardo, and befriended the duke's son, Don Fernando. Fernando had coerced a young woman named Dorotea into agreeing to marry him, but when he met Luscinda, he decided to steal her from Cardenio. At this point in Cardenio's narration, however, Quixote interrupts, prompting Cardenio to leave in a fit of violent madness. Quixote, inspired by Cardenio, decides to imitate the madness of various chivalric knights, and so sends Sancho away.
Coming to an inn, Sancho encounters the barber and the priest, who have been following Quixote with intentions to bring him back home. Following Sancho into the mountains, the barber and priest encounter Cardenio for themselves. Cardenio, back to his wits, relates his complete story to them: after sending Cardenio away on an errand, Fernando convinced Luscinda's father to let him marry Luscinda instead. Luscinda then wrote to Cardenio, telling him of the planned wedding, and of her intentions to commit suicide rather than marry Fernando. Cardenio arrived at the wedding and, hidden, saw Luscinda agree to the exchange of vows, then promptly faint. Feeling betrayed, Cardenio left for the mountains.
After concluding his story, Cardenio and the two other men stumble upon a woman, who is revealed as being Dorotea. Having been scorned by Fernando, she had traveled to confront him, only to learn the events of the wedding, including the discovery of a dagger on Luscinda's person after her fainting, and how she later ran away to flee Fernando and find Cardenio. Dorotea had then been driven into the mountains after her accompanying servant tried to force himself on her.
Reinvigorated by their meeting, Cardenio and Dorotea resolve to help each other regain their respective lovers. After helping the barber, the priest, and Sancho lure Quixote out of the mountains, Cardenio and Dorotea return to the inn with the others. At the inn, Cardenio and Dorotea find themselves suddenly reunited with Fernando and Luscinda. Cardenio and Luscinda redeclare their love for each other, while Fernando repents and apologizes to them all.[7]
