Not only is this dazzler by far the best and most thrilling of the three Harry Potter movies to date, it's a film that can stand on its own even if you never heard of author J.K. Rowling and her young wizard hero. Director Alfonso Cuaron, taking the reins from Chris Columbus, who made a slog of the first two films, scores a triumph by bringing lyricism, laughs and dark magic to the party. Cuaron's 1995 A Little Princess was a favorite of Rowling's. But others wondered what the Mexican director of the erotic road movie Y Tu Mama Tambien would do with Harry (Daniel Radcliffe, 14), Hermoine (Emma Watson, 14) and Ron (Rupert Grint, 15) on the road to puberty. Snap out of it, freaks. Screenwriter Steve Kloves, ever faithful to Rowling, doesn't mess with overt sex, though it must be something of an in-joke that Harry is first discovered under bedcovers playing with his wand. Cuaron knows how to loosen up his pubescent wizards as they head for their third term at Hogwarts. They dress and sass like modern teens with hormones raging. It's irresistible fun watching them grow up onscreen. Radcliffe comes into his own as Harry, giving the role scrappy humor and surprising depth. With the help of his pals and Professor Lupin (the excellent David Thewlis), Harry must cope with an escapee from Azkaban prison (a haunting Gary Oldman) who may have been involved in the murder of Harry's parents. Everyone in this film has secrets (deep, dark Freudian ones) that rival the scary effects, which include a killer tree and soul-sucking creatures called Dementors. Like the book, the movie is long and occasionally long-winded, but it's also a great, twisty ride.