In his first two years at Hogwarts School of

Wizardry and Witchcraft, J.K. Rowling's boy wizard learned to use a magic wand like Glinda the good witch, fly a broomstick like Glinda's evil counterpart of the West (or like Wendy the Good Little Witch), generate light from the tip of his wand like Gandalf the Grey (whose implement of choice was a staff) and use various magical formulae that brought about their results as mechanically as the spells of Cinderella's fairy godmother (“But the thingamabob that does the job is bibbidi-bobbidi-boo”).

Gratifyingly absent from Harry's course of study in fantasy magic was anything notably reminiscent of real-world modern-day occult practice — no séances, no rituals, no Wiccan practices, no crystals or charms.

Now in his third year at Hog-warts, Harry finally has a course involving a pursuit specifically forbidden by the Catechism of the Catholic Church: divination. Under the tutelage of dotty Professor Trelawney (Emma Thompson), Harry peers at tea leaves and gazes into a crystal ball.

This problematic element in Harry Potter and the Prisoner of Azkaban is partly though not entirely mitigated by the fact that Trelawney is depicted as ridiculous and her art as highly suspect — in marked contrast to the more reliable disciplines of other faculty members (a fact emphasized even more pointedly in the book, in which Dumb-ledore comments that he can recall only one time Trelawney ever got anything right).

Trelawney might be best taken as a satire of divination, but still to associate such practices as fortune-telling, astrology and the like with the harmless make-believe of hippogrifs and invisibility cloaks would be both wrong and potentially dangerous. (For more on the moral issues of magic in the Harry Potter stories and in fiction generally, see my article “Harry Potter vs. Gandalf” at DecentFilms.com.)

As entertainment, many fans consider Rowling's third excursion into Harry Potter's world the best of Harry's adventures to date. The film version, directed by Harry Potter newcomer Alfonso Cuarón (A Little Princess) after two-time Harry Potter director Chris Columbus stepped aside, has the makings of the most entertaining of the three films so far. Where Columbus was content to reverently visualize his source material, Cuarón successfully imagines it as a movie.

The first two films were slack at times; here the story is taut and well-paced. The three leads, Daniel Radcliffe (Harry), Emma Watson (Hermione) and Rupert Grint (Ron), inhabit their characters more comfortably and convincingly than ever. Perhaps they're simply growing into the roles or perhaps credit is due to Cuarón for eliciting these performances.

There's a sense, though, in which The Prisoner of Azkaban is a victim of its own success. Where its predecessors felt a bit padded and over-long, this one feels incomplete and overly edited. If the first two films could easily have been tightened up by a half-hour or so, Prisoner left me feeling for the first time as if the story could benefit from an “extended edition” DVD, as with the Lord of the Rings films.

This isn't just because Cuarón has turned the longest of the first three books into the shortest of the first three movies. Rather, it's because important elements included in the films no longer totally make sense, or have the necessary significance, in the absence of what the film doesn't tell us or show us.

For example, Harry, Hermione and Ron visit a rundown cabin called the Shrieking Shack, but we're never told why it's called that, nor what connection it has to events or characters in the story. A delightful artifact called the Marauder's Map is introduced, and one character displays a surprising knowledge of its workings, but its history and connections to the characters and story are likewise left unexplained.

Two characters turn out to have a talent for a certain kind of transformation, and a third character also has a transformation issue, but once again the connections, the history, the relationships aren't clarified. A fourth character, present only in spirit, is never explicitly connected either to the transformation theme or to a key plot point toward the end of the book — which leaves that plot point without any explanatory context at all.

In the book, these are all key plot points. Obviously the film can't do everything the book does, but at least whatever it does do, it should make sense of. Oddly, The Prisoner of Azkaban is the only film so far not to feature a dénouement wrap-up speech from Headmaster Dumb-ledore (Michael Gambon, more than ably replacing the late Richard Harris). Two or three minutes of Dumb-ledore explaining the finer points of the plot to Harry and/or Ron as well as the audience would have gone a long way.

Even so, taken on its own terms, The Prisoner of Azkaban probably remains the most entertaining of the three films, despite its drawbacks. It might resemble a jigsaw puzzle with about a fifth of the pieces missing, but the resulting picture, though incomplete, is richer and more pleasing than the more nearly complete pictures represented by the first two films.

Creature effects this time out carry more of an imaginative and emotional punch. Buckbeak the hippogrif, a computer-graphic imagery horse-griffin hybrid, has far more character and presence than Fawkes the phoenix from The Chamber of Secrets or the Cerberus-like three-headed dog from The Sorcerer's Stone. And neither the basilisk nor the troll from earlier films holds a candle to the wraithlike, hooded Dementors, truly creepy creations that hold up surprisingly well so soon after Peter Jackson's terrifying Nazgûl.

One creature effect, unfortunately, isn't nearly as impressive or dynamic as it should have been. At a key crisis one of the heroes casts a spell that involves the appearance of an animal, but because the animal's significance is never clarified and the animal itself doesn't actually do anything, it's almost a throwaway effect.

This is especially unfortunate because this creature is a sort of icon of goodness opposed to the Dementors, in much the same way as Fawkes the phoenix was an icon of goodness opposed to the basilisk in The Chamber of Secret s. And, much like Fawkes, this creature never matches the impact created by its own opposition. The icons of goodness just aren't as impressive as their evil counterparts.

Magic isn't the only morally problematic issue. Harry's patterns of reckless rule breaking and his near inability to turn to adult authority such as Dumbledore when such help is obviously needed are ongoing problems.

On the other hand, as Christian critic Peter Chattaway points out, The Prisoner of Azkaban also gives Harry his first meaningful relationship with a sympathetic adult, as well as an important emotional connection with another surprisingly sympathetic adult. As Harry grows up, it's nice to see the stories growing up in certain ways, too.

Content advisory: Some frightening scenes and menace; a few instances of minor profanity; fantasy presentation of magic.

Steven D. Greydanus, editor and chief critic of DecentFilms.com, writes from

Bloomfield, New Jersey.