They immediately come upon thirty to forty windmills that appear as giants to Don Quijote. He tells Sancho that he is going to kill them all; keeping their treasures for themselves and doing God a favor by removing their evil from the earth. Sancho tries to convince his master that these are windmills, but to no avail as Don Quijote charges at them amidst Sancho's screaming. Suddenly, a windmill that had been still, is put in motion by a strong gust of wind. One if its sails breaks Don Quijote's spear, then lifts and drops both him and Rocinante to the ground. Sancho runs over and says he warned him they were windmills. Don Quijote has a better theory: that Freston the magician (who stole the library and books) changed the giants into windmills in order to frustrate Don Quijote.
After they remount their horse and donkey, the two begin another of their incredible conversations. Sancho says he believes Don Quijote's version of the windmill incident. Don Quijote explains that he cannot complain of the pain in his half-dislocated shoulder since knight errants never complain. Sancho says he hopes that this rule does not apply to their squires; since, he himself groans at even the slightest pain. Don Quijote, cheered by his squire's honest simplicity, laughs and reassures him that the rule does not apply to squires and gives him permission to complain.
After a night's rest, he gives Sancho further instructions on his squirely duties. He explains that Sancho is never to draw his sword against a knight in any efforts to aid his master, (since he is not one himself thereby making it illegal). However, he may defend Don Quijote against commoners. Sancho explains that he is a peace-loving man, but will defend himself against anyone trying to injure himself, be they knight or otherwise.
A pair of Benedictine friars riding on mules and wearing dust-goggles, (as well-off travelers at this time did), appear ahead on the road. Following them, but not traveling with them, is a coach surrounded by several people on mules, and two muledrivers on foot. With their dark robes and masked faces, Don Quijote's madness transforms them into devils abducting a princess and he demands that they release her. As they protest their innocence, he loses his patience and using his new lance (fashioned from a tree branch and his old spearhead) rushes at them. One gallops away, while the other drops off his horse, just escaping serious injury. Sancho begins removing the friars' frocks, explaining to the muledrivers that the frocks are the prizes from the battle. They beat up Sancho and help up the friar who quickly leaves.
Don Quijote introduces himself to the lady in the coach and asks that she return to Toboso, present herself to Doña Dulcinea and tell her of his deed. One of the horsed pages, a Basque, told him to get lost or he will kill him. They proceed to battle like mortal enemies; the page using a cushion as a shield. The chapter ends with the narrator explaining that the original author did not know how this all ended but promises to try to find out.
