Don Quixote side-story

I came here from Wikipedia's page on "Don Quixote". According to the page, this film was based upon a story from that book and I was curious to find out which one and whether the movie would be good.

Anyway, that page was right. It's the side story of

Cardenio: Luscinda's fiancee who lives as a madman in Sierra Morena Mountains after seeing her wedding.

Luscinda: She was Cardenio's fiancee first and then Don Fernando's.

Don Fernando: The cad who 'wed' and bedded Dorotea and tried to steal Luscinda from Cardenio.

Dorotea: She is Don Fernando’s jilted wife. She also played Princess Micomicona and miraculously changed the character of Don Fernando.

http://www.bookrags.com/notes/dq/CHR.html

This all occurs in volume 1 of "Don Quixote".


** spoilers for Don Quixote **



























From what I remember (without reading those cheat notes):
Don Quixote meets up with Cardenio during his adventures in the mountains and Cardenio tells Quixote his story:
* Cardenio was a middle-class friend of upper-class Fernando and working for Fernando so that he could afford a decent wedding for Luscinda.
* Since Luscinda is so beautiful, he's worried that she may one day cheat on him so someone advises him to test Luscinda.
* Cardenio gets Fernando to try to get Luscinda to cheat on him.
* Eventually Fernando lusts after Luscinda and wants to marry her even though he previously had promised to marry Dorothea just to sleep with her. (Dorothea still regards the scumbag as her fiancee, partly because of her religious conviction.)
* Fernando gets Cardenio taken away or something so he can marry Luscinda. Cardenio gets to the wedding just after she has made vows to him and he goes insane and runs to the mountains.
* Eventually through Don Quixote, they are all in the same inn together and Dorothea makes a persuasive argument for Fernando to keep his promise of marriage to her. Cardenio gets back with Luscinda.