The battered Don Quixote wakes up in the dark and tells Sancho in strict confidence that the beautiful princess of the castle came to his bed to seduce him, but then some enchanted Moor or giant beat him very badly. Sancho complains that the enchanters got to him too, and laments his difficult path as a squire.
Quixote does not have to fall from his imagined reality; the enchanters are there to help him account for the gaps and inconsistencies in his chivalric account of events.
Don Quixote decides to make some of his magic balsam, and asks Sancho to get him oil, wine, salt, and rosemary. The innkeeper gives Sancho what he asks for; Quixote mixes a few pints together and drinks it, immediately throws up, sweats, and sleeps for three hours. On waking, he feels much better, so he concludes that the balsam has worked. Sancho has a much, much worse time with the balsam, until he thinks he’s about to die; he’s left shattered and exhausted. Don Quixote explains that the balsam probably only works on knights; he leaves Sancho to recover and sets out to look for more adventures.
Quixote creates a mixture that is essentially an emetic, a substance that induces vomit. But the Balsam of Fierabras is a potion, not a medicine; it has its effect not through chemical reactions but through a reaction of ideas. The earthly properties of things like oil and salt matter much less to Quixote than their spiritual or magical meanings.
When the innkeeper asks for his payment, Quixote explains that knights do not pay such fees and quickly rides away. The innkeeper then tries to get the money from Sancho, who refuses in similar terms. Suddenly four cloth-teasers staying at the inn decide to have a little fun and begin tossing Sancho into the sky from the middle of a blanket. Quixote hears Sancho’s screams and rides back to succor him, but the cloth-teasers only stop when the fun tires them. Maritornes brings him some water and wine and they soon leave without paying, though the innkeeper takes Sancho’s saddle-bags as payment.
Quixote deals mostly in abstractions of goodness and assistance, but he often fumbles in practice. He knows that knights do good in the world, and that to be a knight one must follow certain unspoken rules, including the rule that knights do not pay for food or shelter. So in theory he is doing good in the world when he refuses to pay, but in practice he is robbing a poor innkeeper.