I love how Rowling creates a complex world and thus avoids black and white painting of things and people. Although the Harry Potter books are a fantasy series, they’re far closer to real life than many contemporary YA novels. An example would be the dementors who are essential for keeping the wizarding world safe as the jailers in Azkaban but on the other hand they are deeply foul creatures.
The same is true of the ending of this third book in the series. While Harry, Hermione and Ron managed to discover the truth, no one, except Dumbledore, believes them. So things aren’t as clear cut as in the first two books anymore. The ending here is not as happy and hopeful anymore. Yes, Sirius’s letter cheers Harry up but the bitter aftertaste lingers and the future seems far less bright than in the previous books. There’s no lightheartedness at the end of Prisoner of Azkaban. Harry and his friends have realized things in the grown-up world aren’t simple and that sometimes you may know you are right but are helpless to prove it. This frustrating helplessness adds to the overall conflict of the series, pointing out how pigheaded and blind even educated grown-ups can be when they’re either scared or have personal interests at stake. Harry, Hermione and Ron don’t just grow in terms of how good wizards they are but also in how well they cope with this unjust world. A good lesson for everyone living in our Muggle world too.