"Harry Potter and the Prisoner of Azkaban"

"The Prisoner of Azkaban" was adapted by Steven Kloves, who also wrote the screenplays for the first two Harry Potter movies. In this, as in the earlier scripts, he shows a good ear for Rowling's lively, unstuffy language. Hogwarts' headmaster professor Dumbledore, played wonderfully by Michael Gambon (stepping into the role previously played by the late, and truly great, Richard Harris), announces that the school's new Care of Magical Creatures instructor will be the beloved, gruff-and-gentle giant Hagrid (Robbie Coltrane). The former teacher, Dumbledore informs his charges, has "retired in order to enjoy more time with his remaining limbs" -- a direct quote from Rowling, and one that captures the mischievous flavor of her prose.

Kloves has also streamlined and sleekened the narrative, which Cuarón paces beautifully: It moves at a clip when it needs to, but it also flows gracefully when it should. And while Kloves and Cuarón may have lost a few crucial details (most notably an explanation of how Harry's father used to adopt the form of a certain animal), they've decanted the essence of Rowling's stories, at last allowing it to breathe on-screen.

Instead of feeling crammed with self-consciously clever details, as the early Potter pictures did, "The Prisoner of Azkaban" inspires a sense of wonder at even the smallest touches: Professor Lupin's classroom features tall, tapered candles that aren't just your typical spirals -- they're shaped like curvy human spinal columns, complete with individual vertebrae. The passing of time is denoted by a graceful pan of the countryside as Harry's white owl, Hedwig, flies across it: Its sun-tinted reds and oranges give way to the sparkling whites and grays of winter. The moving paintings that adorn the walls of Hogwarts have the dark richness of works by the old masters, even as the characters in them chatter and bicker and shuffle around. Cuarón and his cinematographer Michael Seresin even show us the texture of the paint, a surface of swirls and stippling that make these pictures look like real paintings-in-motion, and not just wowee special effects.

And all of the movie's characters, human and non-, seem finally at home in this extremely believable universe. The movie's loveliest creature is Hagrid's beloved Buckbeak, a hippogriff (that's a cross between a horse and an eagle, in case you didn't know), whose bright-eyed expressiveness is as mesmerizing as the swooping of his wings. The most terrifying figures are the Dementors, silent and virtually faceless specters that float in the sky, the tendrilly edges of their shrouds making them look like menacing, silky black squid. The Dementors rank among the most evocative horror images ever put on-screen: I wouldn't advise bringing a very young child to "The Prisoner of Azkaban," considering I'm not really sure I can keep the Dementors out of my own nightmares.

Next page: A fantasy film that's secret is in how very real it looks