Even though our narrator thinks that the nobility are born better at riding horses than lower classes (a pretty dubious claim), the fact is that Sir Guyon is currently horse-less.
Regardless, the Palmer is still Guyon's companion and helps him avoid strong, emotional reactions.
As the two are walking along, they see something very strange approaching ahead: a madman dragging a young man by his hair. Following them is a horrible old woman, mostly lame, with hair growing entirely in front of her face.
As they walk, she hurls insults at the young man being dragged.
Guyon is quite distressed to see this and quickly knocks the old woman away and starts to fight with the madman.
The madmen doesn't fight normally, but rather goes bezerk, punching and grabbing practically at random, sometimes even hurting himself in the process.
Guyon takes him on, but soon finds himself on the ground, which makes him furious. He is about to kill the man with his sword when the Palmer intervenes.
He tells Guyon that his sword won't do any good against this kind of enemy, and says that the man is called Furo—and is constantly troubling knights—and the old woman is his mother and is called Occasion.
The Palmer advises Guyon to first subdue the mother and than worry about Furor, since Furor only knows what to do because his mother tells him.
So Guyon grabs Occasion and stops her tongue and ties her hands and then goes after Furor, who he eventually tackles to the ground and binds in hundreds of iron chains.
That taken care of, he turns his attention to the poor man whom Furor has been dragging and tends his wounds.
Once the man is feeling better, Guyon asks who he is and what happened to him and the man tells his story:
He tells him that all his troubles are due to his so-called best friend Philemon. The two practically grew up together and when the man had the good fortune to fall in love with a great lady, and to get consent from her parents to marry her, Philemon seemed genuinely happy for him.
One day, however, Philemon told him that he suspected his fiancée, Claribell, was not loyal to him. When our narrator demands proof, Philemon arranges to seduce the handmaiden of the fiancée, named Pyrene, and pretend that it's Claribell (apparently, it was, um, super dark outside) while our heartbroken narrator watches (if this is sounding veeery familiar, you're not going crazy, this story is one of many sources for Shakespeare's Much Ado About Nothing).
Furious, the narrator finds Claribell and kills her, after which, Pyrene confesses that it was her, not Claribell, that he actually saw.
Grief stricken, the man poisons his friend Philemon and then tries to kill Pyrene. But while he was looking for her, he got mixed up with Furor and Occasion.
Guyon hears all this and he and the Palmer recommend that the man from now on be guided by temperance (moderation) when making choices, since extreme emotions like anger and jealousy are enemies of love.
But Guyon wants to know the man's name, and he responds that it's Phaon, from the house of Coradin.
But suddenly, while Phaon is answering, they see a squire running toward them carrying an impressive shield with fire painted on that looks like it belongs to an impressive knight.
Guyon asks the squire what he's doing and he answers, haughtily, that this place belongs to his lord, a great and powerful knight named Pyrocles, brother of Cymochles, grandsons of Night and from immortal blood.
He says that Pyrocles loves war and battle and blood and that he, Atin, is his squire.
He explains that he's been sent by Pyrocles to find Occasion since Pyrocles is looking for a reason for a good fight.
The Palmer says that's a terrible idea, no one should look for an occasion to fight, and Guyon tells the squire to relay that to his master.
The squire is not happy about this message, accuses Guyon of being a coward, and throws a dart at him for good measure.
But the dart just rebounds off of Guyon's armor and Atin runs off.