Director Alfonso Cuaron, who is new to the Potter films, and screenplay writer Steve Kloves asserted their independence in making this film adaptation of J.K. Rowling's book. Some touches were added, some scenes from the book were dropped, and others were moved around. And it all works superbly.

....This is the most successful imagining of a Harry Potter book, precisely because it is the least slavish to the book. Film and literature are two very different storytelling media. Simply filming the books almost page for page, which was director Chris Columbus' approach in "Harry Potter and the Sorcerer's Stone" and "Harry Potter and the Chamber of Secrets," quiets the purists but results in a movie that isn't as good as it could have been.

Some fans will complain that the "Azkaban" script omits some important points from the book, but it's already over two hours long.

It doesn't take Professor Trelawney's crystal ball to foresee that Potter fans will embrace "Azkaban" as the best film adaptation thus far, and the one that future Harry Potter movies will strive to match. A.O. Scott in the NY Times:

"Harry Potter and the Prisoner of Azkaban" - which opens nationwide tomorrow, with some midnight showings tonight - is the best of J. K. Rowling's books so far. It balances the narrative economy of the first two with the thematic depth and imaginative ambition of its ungainly sequels. And Mr. Cuarón's adaptation, from a screenplay by Steve Kloves, more than does it justice.

This is surely the most interesting of the three Potter movies, in part because it is the first one that actually looks and feels like a movie, rather than a staged reading with special effects. "Sorcerer's Stone" and "Chamber of Secrets," both directed with literal-minded competence by Chris Columbus (who has stayed on as a producer) may have been more faithful to Ms. Rowling's text, but "Azkaban" attempts, and for the most part achieves, a trickier sort of translation. This film may disappoint some dogmatic Old Hogwartsians: a few plot points have been sacrificed, and Mr. Cuarón does not seem to care much for Quidditch. But it more than compensates for these lapses with its emotional force and visual panache.

Mr. Cuaron's wizard world, shot by the gifted New Zealand-born cinematographer Michael Seresin, is grainier and grimier than Mr. Columbus's. It feels at once more dangerous, more thoroughly enchanted and more real. While the two first episodes took place mostly in the corridors and classrooms of Hogwarts, this one lingers in the shadowy forests and damp meadows outside the school walls, a setting that emphasizes Mr. Cuarón's knack for evoking the haunting, sensual power of the natural world.