The Tale of Despereaux is not just about a mouse, a princess, some soup and a spool of thread. It's about bravery, forgiveness and redemption , and how one small creature teaches a kingdom that it only takes a little light to show the truth: what you look like doesn't equal what you are. This complex three-part story come from a children's fantasy book written by Kate DiCamillo, which won a Newbery Medal in 2004.

Narrated by Sigourney Weaver, the story beginning with the description of our eponymous hero, a tiny, sickly castle mouse with huge ears named Despereaux Tilling. Born with his eyes wide open, Despereaux is the only living mouse of his mother's last litter and has been named by her from the many despairs of their time. He is unlike his fellow mice. He is unafraid of all the things that mice should be afraid of, carving knives, cats, etc, which makes him quite unpopular and shunned by many of those around him. He chooses to read books, instead of eat them, and develops a fascination for fairy tales where he learns about chivalry and courage. With his large ears, he attentively listens to the music played by the king and his daughter. This is how he meets and falls in love with Pea, a human princess. However, we are not introduced to him for quite some time, as we must first meander through some confusing narrative twists. We must follow a sea-faring rat named Chiaroscuro - Roscuro, for short - (voiced by Dustin Hoffman) who causes a lot of trouble when he falls into a bowl of soup. But it's not just any soup. It's the bowl of soup of the queen of Dor, a country where soup is the national passion. The most important day of the year is the day the new soup presented by the royal chef (voiced by Kevin Kline), a true artiste with a muse made of vegetables. Curious Roscuro accidentally falls into the queen's soup tureen, causing her to have a fatal heart attack. The grieving king outlaws soup, and orders that all rats return to the darkness. Angering Roscuro, who would like nothing more than to live above ground, he vows to seek revenge on the king and his castle. With the kingdom cold and sad, the skies perpetually overcast, but rain is never released.

As said, a small mouse with very big ears named Despereaux (voiced by Matthew Broderick) cannot seem to learn important mouse skills, like cowering. Brave, adventuresome, and chivalrous, Depereaux is a complete gentleman. Despite the mouse community's general mistrust of humans, Despereaux has fallen in love with a princess named, Pea. His interactions with the humans angers the mouse community, and he is sent to the dungeon, which is filled with rats. There he meets the jailer, Gregory, who offers to save him in exchange for being told a story.

Meanwhile, a scullery maid named Miggery Sow - Mig, for short - sees Princess Pea taking a horseback ride. This gives Mig hope that she can now be the princess, which has been her greatest dream. Traded into bondage by her father in exchange for a hen, a handful of cigars, and a blood red tablecloth, Mig is set to work in the castle dungeons, where she meets Roscuro, who manipulates her into kidnapping Princess Pea, so that she can remain in dark forever.

As the rats capture Princess Pea, Despereaux attempts to save his beloved, only to get his tail chopped off. Will Despereaux ever find his beloved Princess Pea and save her from the rats? Or will to forever spend her days in darkness? Despereaux knows that he is the only one who can rescue her, but can the tiniest mouse find the courage of a knight in shining armor?