How It All Goes Down
Despereaux is different. Very, very different.
Our story begins with a birth of a tiny little mouse named Despereaux in a castle in the Kingdom of Dor. He's an oddity to his mouse family; he's not interested in your normal mouse activities. He'd rather read a book than nibble the pages; he doesn't like to hunt for food. Even his mother's a little disappointed in him.
One day, Despereaux hears a lovely sound and wanders into the human Princess Pea's bedroom to find her father King Phillip playing the guitar and singing. It's love at first sight. Despereaux approaches the princess and tells her that he honors her (he's been reading a book about knights and princesses). He's so smitten that he's forgotten Mouse Rule #1: Don't let humans see you. Despereaux pays a terrible price for forgetting: He's sent by the Mouse Council to the castle dungeons, where he's sure to be eaten by the rats who live there.
This is an awful, terrible, no good, very bad fate, but Despereaux tries to stay strong and think of the princess. He tells himself a story aloud to keep up his spirits as he descends the steps. Gregory the jailer scoops him up and decides to save Despereaux in exchange for a story. (Things get very lonely and depressing down in the dungeons.) He wraps up Despereaux on a napkin and puts him on his empty dinner tray to be taken back upstairs.
The book jumps back in time to introduce us to Roscuro, a rat who grows up in the dungeons and is supposed to enjoy torturing prisoners for fun. He practices on a prisoner who's confessed to trading his daughter for a hen, some cigarettes, and a red tablecloth. But this brings Roscuro no pleasure. What he really longs for is to be a part of the bright upstairs world.
One day, he sneaks up to the castle and climbs on the chandelier during a royal feast. The princess sees him, and a startled Roscuro falls into the queen's bowl of soup. The queen promptly dies of fright. Roscuro goes back into the dungeons to plot his revenge against the princess. He remembers her look of disgust at seeing him—a rat—and can't forget how it made him feel.
In the meantime, we meet a little girl named Mig who's sold into slavery by her father in exchange for a chicken, some cigarettes, and a red tablecloth.
Wait, what?
Anyway, Mig slaves away for the nasty man she has to call Uncle, who clobbers Mig in the ears every chance he gets. One day, she sees the royal family passing and decides that she wants to become a princess. When the king's men come to collect all the soup utensils from everyone in the kingdom (they're illegal now, too), they find Mig working at Uncle's house and take her away to the castle to be a servant. Slavery is illegal in the Kingdom of Dor.
Mig is so useless as a servant that she's soon assigned to the worst job ever—bringing meals to Gregory the jailer in the deep, dark dungeons. To reassure herself on her way down, she talks to herself about how she wants to be a princess. Roscuro overhears her and realizes that he can manipulate this simple girl into doing his bidding. He convinces Mig to help him kidnap Pea, after which Mig will be the princess and Pea will be her servant.
Despereaux overhears Roscuro explaining his devious plan. He stows away on the jailer's empty tray and heads back upstairs to warn the princess. But he falls asleep after an exhausting encounter with Cook and a knife, and when he wakes up, Pea's already been kidnapped at knife point and led down to the dungeons. Loyal knight that he is, Despereaux decides that he'll have to go to the dungeons himself and rescue the princess.
In the end, Despereaux holds off Roscuro with his knight's lance—oops, make that a sewing needle. With Mig's help, he saves the princess and they all return to the castle. Instead of punishing Roscuro, Princess Pea takes pity on him and gives him free run of the castle. Roscuro, to his credit, tells Pea about the prisoner in the castle who sold his daughter. She reunites Mig with her father, who feels so awful about abandoning Mig that he treats her like a princess for the rest of her life.
And as for Despereaux and the princess? They live happily ever after as the best of friends. This is a fairytale, after all.