One of the reasons the story is so much darker is the Dementors, the guards of Azkaban. Posted around Hogwarts to guard against Black, Dementors feed on everything cheerful and happy, leaving anyone in their presence feeling miserable. Vaguely humanoid forms, cloaked completely in black, the Dementors turn the air ice cold when they approach. Soul-sucking monsters tend to add a darker tone to any movie.

Of course, the primary strength of the movie is the chemistry that the main character actors bring to their roles. Daniel Radcliffe, Emma Watson, and Rupert Grint as Harry Potter, Hermione Granger, and Ron Weasley, respectively, have very much grown into their roles, and through the experience of making three feature-length films have strengthened the bond between them just as much as their fictional counterparts have through their years of schooling together. The dynamic between new Professor Remus Lupin (David Thewlis) and Potter, as the young wizard learns about his father from James Potter’s friend and schoolmate.0

Although Gary Oldman, who plays Sirius Black, was not on screen for most of the movie, he does an excellent job as the ragged, desperate convicted murderer. Black turns out to be Potter’s godfather, and perhaps not as crazy as he seems.

The only real fault of the movie was the omission of several plot lines from the book, most notably Harry receiving the Firebolt mid-winter, Gryffindor winning the Quidditch Cup, Peeves the Poltergeist, and a dozen other more minor details. Also, the layout of the Hogwarts grounds, namely the front entranceway, the location of Hagrid’s hut, and the location of the Whomping Willow, are all changed from the previous movies.