Principal Cast Daniel Radcliffe -- Harry Potter Richard Griffiths -- Uncle Vernon Adrian Rawlins -- James Potter Geraldine Somerville -- Lily Potter Gary Oldman -- Sirius Black Rupert Grint -- Ron Weasley Emma Watson -- Hermione Granger Julie Walters -- Mrs. Molly Weasley David Thewlis -- Professor Lupin Michael Gambon -- Albus Dumbledore Alan Rickman -- Professor Severus Snape Maggie Smith -- Professor Minerva McGonagall Robbie Coltrane -- Rubeus Hagrid Emma Thompson -- Professor Sybil Trelawney Julie Christie -- Madame Rosmerta

In regards to the Harry Potter phenomenon, I've come late to the party. I haven't read any of J.K. Rowling's ubiquitous novels, and I managed to avoid the first two enormously popular film adaptations directed by Chris Columbus. Small British schoolboys waving their wands and shouting Latin -- sorry, but it all simply wasn't compelling enough to garner my interest.

But when I heard that Alphonso Cuarón, the Mexican director of the NC 17-rated Y Tu Mamá También, had taken on the assignment of Harry Potter and the Prisoner of Azkaban, I was too intrigued to ignore this series any longer. And what a fantastic addition Cuarón has proven to be, lending maturity and depth -- and a surprisingly great amount of visual beauty -- to a tale of a boy wizard. And if much of what lies in Prisoner of Azkaban is old news to Potter's longtime fans, it was at least as new to me as it was to Cuarón, who had to be cajoled into reading the script when it was sent to him. That it works for a neophyte as myself -- and for an initially resistant director -- is a testament to its magic.

There are stories for kids and then there are stories about kids, and HP3 (as I'm going to call it from now on) is one of the latter. Its subject is the adolescent transition from childhood into adulthood, and it gladly doesn't pander to an audience that it knows has, by this time, grown old enough to appreciate (often painfully so) that transition, and the often symbolic storytelling used to render it here. Screenwriter Steve Kloves (who turned out the previous scripts) keeps his thematic material in the open, without letting it spoil in the air of easy sentiment and cliché. The basic method is to complicate things that at first appear simple, and then show how one can adapt with humour and integrity, as Harry absorbs the moral conundrum that sometimes friends can be enemies, and enemies, friends.

As we meet him, young Potter is in the indifferent care of his Uncle Vernon (Robert Griffiths). (As a fair neophyte to the larger narrative, I was relieved to find that the backstory of Harry's parents having been murdered by Voldemort -- you may know who he is; I didn't -- was easy enough to pick up when it was warranted.) When Uncle Vernon's sister (Fiona Shaw) makes a visit, Harry comes in for some verbally rough treatment from his aunt that's usually found only in Dickensian novels featuring orphans. He weathers it as well as he can, though he draws the line when she makes his parents' memory the object of her abuse; the boy's response is deform her with a spell that inflates her like a large balloon and then floats her out the window and over greater London.

It's a moment both gruesome and comic, and reminded me of the classic Twilight Zone episode "It's a Good Life," in which a young Bill Mumy holds the adults in a small town in near-constant terror with his power to realize anything he can imagine. All of HP3 has that similar tone, blending the comic and the horrific in a way that highlights the basic swing of the story's emotional intelligence, leavened with a great deal of hope and patience the further you get into it.

Harry is moved to run away, first to a kind of sorcerer's way station (the nicely named Leaky Cauldron) and from there back to school, the Hogwarts Wizards Academy, whose campus is what I imagine fantasist Philip Pullman would do with Brideshead Revisited, if he removed the homoerotic subtext. The campus is soon under a lockdown, watching for the appearance of a character known as Sirius Black (Gary Oldman), a malcontent who was found guilty of betraying Harry's parents to their murderer, has improbably escaped from the notorious Azkaban Prison, and may pose a mortal threat to the young Harry. Guarding Hogwarts are creatures known as Dementors, ghastly spectres that draw out our fears in order to feed on them and make us weak. Their realization by the wizards at ILM (and assorted special effects houses that lent a helping hand for this film) is flawless and thrilling; their introduction while investigating a train is a standout moment of art design, writing and directing that defines how dark and unnerving this film can be. (Here's a good place to remind you that the very young may find the consistently dark tone of HP3 to be unsettling, and the idea of taking them to see this should receive cautious consideration.)

Guiding the students -- and occasionally chiding them -- are a colorful array of instructors: the myopic seer of destinies Sybil Trelawney (Emma Thompson), who gives Harry a grim foreboding of the future; the stern and suspicious Severus Snape (Alan Rickman); the genial and trusting giant Rubeus Hagrid (Robbie Coltrane); and of course the wise, fatherly headmaster Dumbledore (the always fine Michael Gambon). New to the faculty is Professor Lupin (a terrific David Thewlis), a young teacher whose own past trauma makes him peculiarly sensitive to Harry's predicament. I like the way these characters are sketched with quick strokes and bright colors and quirky touches, leaving the cast to fill in the gaps and round them off; if J.K. Rowling is able to marshal the same depth in her prose, then I can begin to understand the success the books have enjoyed.

The three principals are terrific and have a natural chemistry. Daniel Radcliffe nails the proper tone for each scene he's in (which is practically all of them), Rupert Grint has a wonderfully expressive face and great comic timing, and Emma Watson, at the tender age of fourteen, already has the talent and intelligence to cast a formidable screen presence. I hope the producers find a way to keep them together for all the future films.

In a story where doubts about one's character, even one's very nature, are thematic, it makes sense that almost everything is literally alive, from candles floating in mid-air, to the animated pictures in newspapers (Sirius Black silently and continuously screams out from beneath a front page headline), to the way inanimate objects work industriously on their own. Cuarón and Kloves (and Rowling, I presume) show a resourceful creativity here. Everything in this world is capable of transformation and therefore worthy of suspicion. A particular tree called the Whomping Willow is a great symbol of the dark and twisted funk that hangs over our newly-teenaged heroes. It amuses itself by occasionally pulverizing a wayward bluebird of happiness; its carnivorous nature threatens the kids directly when they have to tread a path beneath it (literally) that leads to confrontations and revelations that the film has been pointing towards.

And then the movie does something fairly bold and innovative for a summer money-grab: it repeats its climatic final act from another point of view, using time travel in a way that develops plot points even as it underscores the importance of time to the construction of our individual characters. The two halves of the total sequence cleave together perfectly in an innovative bit of narrative dancing. Splendid.

I'm still stunned at how this movie keeps throwing one ingenious idea after another at you while keeping its themes front and center. I haven't mentioned the scenes involving the hippogriff, for example; or the class where Lupin forces his charges to literally laugh down their fears; or the map that shows when and where people are stalking about in Hogwarts -- even the dead; or Harry's use of a cloak of invisibility; or the werewolves; or the bus ride; and so on. This film is an Ali Baba's cave of riches, appropriate for both adults and near-adults. For the first half of 2004, this -- regardless of genre -- is about the best film you can hope to see. Count this "muggle" as converted.

David Newbert worked for public and university libraries for several years before joining the college book trade. He lives in New Mexico, where the aliens landed.