1. J.K. Rowling’s third Harry Potter novel Harry Potter and the Prisoner of Azkaban starts in the third year of Harry’s schooling at Hogwarts. In the novel, much of the backstory about his parents is revealed, along with his first encounters with Sirius Black and the dementors. Over the course of the novel Harry believes Black was the one to betray his parents, but comes to learn Black is his godfather, was a close friend of his father, and was wrongly imprisoned for killing Peter Pettigrew, who is alive and is the actual traitor. Pettigrew eventually escapes Black and Remus Lupin’s clutches after Lupin turns into a werewolf. This forces Black to remain in hiding because he cannot clear his name, but the book ends on a high note, as Harry is happy he has a wizard family member looking after him and a father figure again.
2. The film version of Rowling’s novel is a condensed version of the book adapted to the screen. It follows the same basic plot of the book–Harry returns to Hogwarts for his third year of school, aware Sirius Black, believed to be the one who betrayed his parents, has escaped wizard prison Azkaban. In the film Harry’s emotional development is sped up thanks to the condensed plot, leaving out some of the romantic development between him and Cho Chang that builds in the next two books.
3. The adaptation maintains the main story of the book, but cuts out most of the excess parts of the book, which was necessary for the book’s length. Certain key parts of the book were also cut out, like Sirius Black’s backstory and his escape from Azkaban, but it does not detract from the film. The order of some events are also changed, such as when Harry receives the Firebolt; in the novel it comes at Christmas anonymously from Black and is seized by McGonagall on speculation it might be jinxed, while in the film Harry receives it at the end, as a sign of the new relationship between Harry and Sirius. However, some character development is added to the film that wasn’t present in the text. Hints of Ron and Hermione’s romantic relationship in the later films are present in the film, as is Harry’s rage and dark side, which he shows when he is enraged by Black and is readying himself to kill him when they inevitably meet.
This was a pretty fascinating read on the time travel sequence at the end of the film. The author of the analysis says that six separate timelines are necessary to create the sequence in the film, with Harry dying in each of the first three timelines (he is killed by Lupin because no one intervenes in the first timeline, is killed by dementors after Hermione calls Lupin but is unable to intervene further, and is killed again by dementors when he tries to reach the other side of the lake to save Sirius). In the final three timelines, Harry lives, but at a cost in the first one: Sirius gets his soul sucked out because he is not strong enough to intervene (in the second, the time-traveling Harry helps Harry and Sirius, but the author says Harry must go back one final time now armed with the confidence that he will be strong enough to stop the dementors–all this time travel hurts my head). The author says that the film fixed an anomaly in the book that would’ve made Harry’s survival logically impossible–Harry and Hermione travel to the shore of the lake together to find who casted the Patronus, not just Harry himself, as he would’ve been overwhelmed by the dementors on his own.
I didn’t want to use a review here, but I found that first paragraph interesting: Cuaron’s film took the longest book in the series at the time and cut it down into the shortest movie of the first three. The author of the review goes on to say that the first two films were criticized for trying to cram everything from the source text into the film, something Cuaron avoided.
This is a complete listing of all the differences in the book from the film. One I didn’t realize: Cuaron has Gryffindor win the Quidditch Cup, something they didn’t do in the first two books and hadn’t done going back seven years in Rowling’s universe.
5. Cuaron’s Prisoner of Azkaban is definitely darker in tone than the two previous films, caused by the more violent, dangerous sequences in the movie. Although the previous films had vital characters that either died before the book or were vanquished by Harry, the books and films don’t explore death fully until the third installment, when the events of James and Lily’s death at the hands of Voldemort start to get explained, and the idea of Sirius Black as a cold-blooded murderer is held almost through the entire film. The characters are darker as well–Lupin is noble but transforms into a werewolf, Sirius’s animagi is a black dog, and at one point an executioner is featured and guillotines a Hippogriff offscreen. The final sequence of the film features Sirius’s “death” at the hands of the dementors, and Harry hearing the final cries of his mother as he is attacked by the dementors. Harry’s emotions are also darker in the book and the film; almost through the entire course of the film he and Ron are distant from Hermione and he readies himself for a showdown with Sirius, who he believes to be completely evil. Cuaron’s “darker” characters give the Patronus Harry casts to save his past self and Sirius a much more poignant moment; it is there that Harry’s transition from young, angry pre-teen to matured, strong leader begins in the series.