The second part of Don Quixote was written in response to a false second book written by an author other than Cervantes, and we hear about this imposter quite a bit. This installment is more plot-driven than the first, so it flows a bit better as a story instead of presenting lots of little, unconnected snapshots. Sancho Panza is a good deal wiser than in the first part: he proves himself astonishingly capable at governance, and wily enough in his own right to manipulate situations to suit him.
Other than these small changes, the second part is much the same as the first. Don Quixote is utterly mad then completely coherent by turns, and his words and actions never cease to amaze even those who had read about him in the first part of his history. Due to people knowing of him, various tricksters devise humorous adventures for him, and though they laugh at him, no one can deny his general good sense. And as graciously as he lived, Don Quixote dies, "cured" of his madness but no less gallant for it. This novel is truly a treasure that people will enjoy for yet more centuries to come.