The content of Harry Potter And The Prisoner Of Azkaban.

It's about Harry and his godfather Sirius. . Sirius was mistaken for a murderer at first, and Harry thought he betrayed his parents. Later, Sirius escaped from Azkaban and went to Hogwarts. With the help and explanation of Lu Bang, he met Harry and cleared up the misunderstanding. Harry and others also helped Sirius escape from the Ministry of Magic. . . Maybe so, but there is also a mention of Wormtail who really betrayed Harry's parents. . This part paves the way for the fourth and fifth parts. .