The company sympathizes with the captive and Zoraida, and each wishes to help them. Suddenly more guests appear at the inn although there is hardly any space to accommodate them. The newcomer, accompanied by his young daughter Clara, is a rich and influential judge, on his way to a new appointment in the Indies. The captive recognizes that the guest is his brother, and everyone sheds new tears to witness the tender reunion. The judge and Clara embrace Zoraida warmly and tenderly. When at last everyone retires, the ladies agree to share the garret, the men find sleeping space without, and Don Quixote stands guard outside the castle. He wishes to protect the ladies "lest they be attacked by some giant or wandering rogue of evil intent who might be covetous of the great treasure of feminine beauty within these walls." In the middle of a peaceful night, everyone awakens to listen to the beautiful singing of a mule driver.
Dorothea awakens Clara so that she too can hear the music. The young girl is overcome by sobbing. She explains that the singer is not a muleteer, but a young man of rich background who follows wherever she and her father travel. Because they are both so young sixteen years and because Don Luis' father is so wealthy and influential, the couple cannot marry, no matter how deeply they love each other. Dorothea soothes the sobbing Clara until she falls asleep.
Meanwhile, Maritornes and the landlord's daughter play a trick on Don Quixote as he stands guard on horseback. The girl softly calls him, and the knight, assuming as before that she is in love with him, bids her to withdraw her attentions because his heart already belongs to Dulcinea. Maritornes begs him merely to extend his hand so that her mistress might satisfy her passion a small amount. Don Quixote complies, standing on the saddle to reach the loft window. Maritornes quietly slips a knot over his wrist, tying the other end of the strap to the bolt on the door. Thus imprisoned, Don Quixote can only assume that he has been enchanted. Rosinante, remaining as immobile as a statue, reinforces his judgment; the knight fervently hopes that his horse remains still. At dawn, however, four horsemen arrive at the inn, and Rosinante gently turns to sniff at one of the mounts. His foot slipping from the saddle, Don Quixote is left dangling by the arm in a most painful manner.
The bellowing of the poor knight awakens the innkeeper. Quietly Maritornes unties the sufferer and he drops to the ground. The four horsemen identify themselves. They are sent by Don Luis' father to find the son at all costs. The youth remains defiant, and the judge, recognizing his neighbor's child, draws Don Luis into earnest conversation. Meanwhile, the landlord's daughter begs Don Quixote's assistance, for her father is fighting with some guests who wish to leave without paying. Surprisingly, the knight settles the argument by his persuasive reasoning rather than with violence. Suddenly, the very barber whose basin and donkey-trappings had been despoiled by knight and squire enters the gate. Recognizing Sancho, the barber grabs his packsaddle, and Sancho offers him a punch in the nose. Don Quixote intervenes, explaining that the trophy which, looks like a basin, is Mambrino's helmet, but as to the steed's trappings lawful spoils for Sancho he says they have somehow been transformed into a mere packsaddle for an ass.