Harry Potter and the Prisoner of Azkaban is the third book in the mega-popular Harry Potter series that was created by JK Rowling. The book's first printing was in July 8, 1999. The film version of the book was released on May 31, 2004 in the United Kingdom, and shortly after in the United States. The book is one of the most popular volumes of the series. Harry Potter and the Prisoner of Azkaban is distinguished from the other volumes in the series in that it is the only title in which the dark lord Voldemort does not appear.
At the beginning of Harry Potter and the Prisoner of Azkaban opens with Harry spending his summer again at the Dursley's. He celebrates his birthday alone there, although he does receive gifts and cards from his friends back at Hogwarts. He also receives a newspaper clipping from Ron Weasley that announces that his father has won a prize that has allowed the family to take a trip to Egypt. The newspaper is also filled with stories about Sirius Black, who is a known insane murderer and who has recently escaped from Azkaban prison. But despite this news, Harry is still more afraid of the visit from his Aunt Marge. When Aunt Marge's insults Harry, he becomes so angry that he gathers his belongings and leaves. Outside on a dark street, he comes upon a large black dog. He stumbles and inadvertently sparks his wand. This summons the Knight Bus which takes him to Diagon Alley. Harry spends the rest of the summer at the Leaky Cauldron.
On the train back to school, Harry, Ron and Hermione spot creatures called dementors, which are guards of the Azkaban prison searching for Sirius Black. The dementors are installed to help protect Hogwarts until he is caught. Meanwhile, Hermione appears to be taking every class available, and Harry is frightened that the dog he saw earlier is an omen of death. Hagrid has trouble adjusting to life as a teacher, and one night the Gryffindor students find that they are locked out of their dormitories. Sirius Black is out to find Harry.
During a quidditch match against Hufflepuff, Harry faints at the end and falls from his broom. The dementors rush toward him, and then run away. Later, Harry, Hermione and Ron sneak into a pub and overhear a conversation about Sirius Black in which they discover that Black was one of Harry's father’s best friends, as well as Harry's godfather. Apparently, Black was also the Potter's secret-keeper, but eventually betrayed them to Voldemort. Harry vows to get revenge against Black.
One of the most popular passages of this volume is when Harry Potter learns the famous patronus charm. Later, Harry, Ron, and Hermione find themselves in the shrieking shack. It is revealed that the new Professor Lupin sometimes turns into a werewolf, and that Harry's dad as well as Sirius Black also turned into animals to help keep him in track. Thus, it is revealed that Black is not the awful character that Harry had thought he was. He is in fact his godfather, and offers to take care of Harry. But Black is captured by and Hermione must use her Time Turner to transport her and Harry back in time briefly. They are able to free Sirius. Later, when it is revealed that Lupin is a werewolf, he resigns, but before he leaves he gives Harry the Marauder Map that he made with Black and Harry's map.
Harry Potter and the Prisoner of Azkaban surely have one of the most interesting and complex plots in the series. It is full of charms, secrets, and plot twists that keep the reader guessing at all times.