Despereaux saves Princess Pea from Roscuro's plot by going to the princess and Mig and then helping them convince Roscuro to let them go.

After Roscuro, a rat, frightened Pea's mother to death, Pea insulted him. He plotted with Mig, a servant girl, to chain Pea in the dungeon forever. When Despereaux, a mouse, gets wind of the plot, he plans to save Pea and warn the king. However, the king won't listen to him.

Despereaux decides to save Pea himself. After getting the thread from the Threadmaster and eating soup that the cook gives to him, he heads into the dungeons and is led to Pea and Mig. Mig has refused to chain Pea, but Roscuro refuses to let them leave the dungeons.

When he smells the soup on Despereaux's whiskers, though, he remembers the night he scared the Queen. Pea promises that Roscuro can eat some soup in the dining room once he leads them out. Everyone enjoys soup together, and Desperaux and Pea become good friends. Mig is reunited with her father, who was a prisoner in the dungeon.

Desperaux is able to bring together multiple characters—principally himself, a mouse; Roscuro, a rat; and Mig, Pea, and the Cook, who are humans, to convince Roscuro to let go of his revenge, save the princess, and help Mig reunite with her father.

The Tale of Despereaux, which was written by author Kate DiCamillo and published in 2003, is a children’s story about a brave mouse. Despereaux has many problems in the story, including being different from his family and the rest of the mouse community. These differences result in his incarceration in a dungeon. However, Despereaux’s biggest problem is the love he has for a human, Princess Pea, as mice and humans should not be friendly.

When Despereaux escapes from the dungeon, he learns that Princess Pea has been imprisoned by Roscuro the Rat. Despereaux tells the King that Princess Pea is in the dungeon, but the King does not believe him. Despereaux is determined to rescue the princess himself. Following Despereaux’s rescue of Princess Pea, the pair are able to become very good friends.

There are a number of elements that might be considered the central problem in The Tale of Despereaux. At the most basic level, the mouse that is the title character is faced with the universal problem of appropriate moral, ethical development. For him as mouse, there are specific ways this problem plays out. Despereaux must learn to function effectively as a mouse in a society that often discriminates against mice. For their own protection, mice are expected to hide from humans.

One problem arises when Despereaux breaks that rule and is punished by imprisonment. Solving his problem then requires him to escape from captivity.

A second problem arises from his love for a human woman, by which Despereaux also rejects the limits that are put on mice. To prove his love and loyalty for the princess, he must rescue her as well as himself.

Despereaux uses a combination of skill and self-reliance, but also draws on help from others to solve these specific problems, and in doing so he grows up quite a bit.

The major problem in The Tale of Despereaux is the unfriendly relationship between the mice, the rats and the humans. Roscuro the rat caused the death of the Queen which forced the King to outlaw all rats. During Roscuro’s escape after the death of the Queen, Princess Pea spoke harshly towards the rat and because of this the rat grew to resent the Princess. After these events, Despereaux, the unusual mouse with unusual physical features was born. Despereaux encounters the princess and gets attracted to her. The mouse is sentenced to the dungeons to be eaten by rats because of the relationship with the princess. Later in the story, Despereaux overhears a conversation between Roscuro and Mig, the royal maid charged with delivering food to the dungeon guard, with the intentions of harming the princess. Due to Roscuro’s trickery both Mig and the princess are held captive in the dungeon and Despereaux goes to save them. Despereaux gets an opportunity to kill Roscuro using a needle handed to him by the threadmaster who encouraged him when he was sentenced to the dungeon. The princess asks Despereaux not to kill Roscuro and the story ends with the main characters seated at the banquet hall having soup, in what seems to be a reunion of the mice, rats and humans.

The efforts of Despereaux help in solving the problem between the mice, the rats and the humans.