Back in Wittenberg, Faustus meets with a horse-courser (horse trader) and sells him his horse. He warns the trader not to ride the horse into water. Faustus begins to worry about his impending death and damnation. He falls asleep.
Though less significant than Faustus' bargain with Lucifer, this deal (which we will soon learn is a bad one) furthers the play's exploration of bargains, deals, and exchanges as potential chances for exploitation.
The horse-courser returns, completely wet, and angrily calls for Faustus. He had ridden the horse out into the middle of a pond (thinking that Faustus' warning was an attempt to hide some magic skill of the horse), at which point the horse turned into a pile of hay and he fell into the water. The horse-courser shouts in Faustus' ear and pulls on his leg to wake him. Faustus' leg comes off, and the shocked horse-courser flees. Faustus' leg is instantly restored, and he laughs at the horse-courser. Wagner arrives to tell Faustus that his company is requested by the Duke of Vanholt, “an honorable gentleman,” (10, 74).
Faustus uses the bargain to cheat the horse-courser, but doesn't seem to realize that Lucifer may be cheating him in their own deal. With the fake leg, Faustus continues to use magic for essentially cheap jokes, further evidence of his degraded character.
In the B-text, Robin and Rafe have a drink at a tavern. At the bar, a carter (a cart-driver) tells them that he ran into Faustus on a road and Faustus paid him to give him all of the hay from his wagon, which Faustus then promptly ate. The horse-courser is also at the bar, and joins in the conversation, telling everyone about the horse he bought from Faustus and how it transformed on the water. The horse-courser acts as if he got revenge, though, by tearing Faustus' leg off, neglecting to tell the other bar patrons that this was only a fake leg. This tavern scene does not appear in the A-text.
This additional scene in the B-text offers more comic relief. The horse-courser's story, in particular, elicits laughs as the audience knows that he is lying. The courser's story shows the continued decline of Faustus, as this use of magic makes him simply grotesque.