Spoilers ahead for the earlier two. . . .
The adventures of Quentyn after he leaves home.
Starting with his helping a thief whom some people are going to kill, and who is less than honest with him. . . turns out to be a girl named Sam, and an elf, who reveals the secret of the elves, who never grow old. That is because they all die about the age of twenty. (Reason given.) Onward to a duchy that proves to have a problem (fortunately has some people who think Quentyn is fae and so should be treated very nicely. We hear of the oppressive duke, and then we learn more.
Volume 3 involves backstory where a girl told a ten-year-old boy that there was a monster under the bed, the language of flowers, the uses of Latin, revoking invitations, throwing pies, the exact words of a challenge, the constraints on the Wild Hunt, the problems of money, and more. The end loops into consequences.
Volume 4, in fact, opens with the same strips (which does make it more coherent), there being dragon problems. and Sam pointing (with picking him up by way of demonstration) that he's two feet tall, a squire charged with impersonating a knight, a strange suit of armor, a nice little horse, a problem with stories, and more. The end's a bit of a downer; more can be found here.