This chapter concerns a trial started to find out if the Knave of Hearts was guilty for having stolen the Queen of Hearts' tarts. The King plays judge, and an assortment of animals are the jury. As always, the Queen's obsession with death threats puts the rules of justice in jeopardy, making all of the witnesses and the Jury very afraid to do their duty. Again, the message seems to be that rules administered by a tyrant are worse than no rules at all; a reasonable attitude towards rules is the hallmark of adult behavior, not just rules themselves.
In the middle of things, Alice starts to grow. The trial goes on a bit longer as Alice grows, until finally she is the one who is called to the stand, which takes us to the final chapter of the book.
The Hatter and his group are called as witnesses. Little Bill is a member of the jury. All in all, this chapter has gathered together a lot of the main players from the book together. It seems the point of this is to bring together the many parts of the novel so that Alice, like a trial lawyer, can make her summation speech.