Spoilers, as you may expect, follow.
First thing to get out of the way; this surpasses the previous two movies to an almost embarrrassing extent. The imaginative, playful use of the production design from the earlier films exposes Columbus's pedestrian directing style like a lumos spell in a cupboard. Hagrid's hut, for example, now sits by a lake at the bottom of a set of vertiginous steps. Hogwarts nestles gloomily in its Glen, a brooding mystery far removed from the Disney castle of Philosopher's Stone. Everything and everywhere feels more magical, more unworldly while still being a convincing world on top of ours.
From the dynamic, punchy opening which gets Harry out of the clutches of the Dursleys for this installment (a mercy), it's obvious that Cuaron gets what makes the books fun. Not necessarily funny - I think I maybe laughed twice, and smiled a lot, but this isn't about the Rule of the Animal - but the zip and zing of the stories. Harry is barrelled along with the audience through an unfolding mystery which frequently threatens to be just too mysterious but is always pulled back by a handy bit of explanation (Steve Kloves just can't get enough of that exposition, it's just a mercy the script editor had had at it this time).
Bigger spoilers
A shame most of us know the big twist, but Cuaron very nearly sidesteps this entirely by keeping Black as little more than a background figure and dispensing entirely of, say, the dormitory break-in. Still, the tension which may have been there is somewhat sacrificed.
Big spoilers end, continuing with regular spoilers. This has been a public service announcement.
So what are we left with? Well, character. And effects. But let's talk about character first.
Thankfully, the performances from the three teenage leads are light-years beyond the dreadful Chamber of Secrets and the merely poor Philosopher's Stone. Radcliffe has grown substantially as an actor and makes a capable lead, dealing with the dialogue like a human being rather than an actor-bot. Rupert Grint has all but given up the mugging and is.. well, not in it that much. However, the real star here is Emma Watson. Sure, there are moments when her performance is as mannered as it has been previously, but for the most part she is fabulous, and it almost feels like Hermione's role has been expanded to reflect this. So expanded, in fact, that one begins to suspect that the next movie will be "The Amazing Adventures of Hermione Granger and her Wizard Pals".
As ever, the adults are also very worthwhile. Except perhaps Emma Thompson, but that's more to do with Trelawney being a dreadful character than her Edina impression. Michael Gambon brings an interesting if insubstantial Dumbledore to the table, while Alan Rickman and Maggie Smith are more or less sidelined but still good value whenever they do make an appearance. It's with Gary Oldman and David Thelwis that the most astute casting has been done, however. Oldman gives Black the soulful depth needed to give the character credibility. Thelwis - who I thought was a disastrous bit of casting when I first heard it - turns in the best adult performance; in his hands Professor Remus is the engaging, charming figure of the books, winning me over completely. His scenes with Harry are character high-spots, and who cares that he's not as good looking as he should be..?
Which leaves, I think, the effects. I wanted to give special mention to these, because they're a cut above. The magical light in the movie is just beautiful to look at - which is good, because Potter is much darker this time out. The dark greys and slate blues require relief, and the golden shimmer of the Patronus charm or the vivid illumination of wand-lights are eye-bathingly gorgeous. They are also used in such a seamless way within the world that it's unquestionably clear that this shit is magic, just as the tiny touches (Remus packing his stuff with a resigned air of magical familiarity, the spiffy Knight Bus hurtling through an oblivious London) are thrown away as simply part of the world.
Magical creatures this time have been really cared for, too. Buckbeak - always a dodgy prospect - has turned out well. Not perfect, but the characterisation shines through the odd dodgy movement (I'm being super-picky here, the Hippogriff looks great). The werewolf transformation is among the best you'll see on screen, right up there with American Werewolf and The Howling, even if the end result looks a bit.. well, it looks a bit like a wolfy Gollum.
Basically, it's like the first two were just showreels. This time out, someone actually picked up the material and made a movie from it. Potter fans, your prayers have been answered.
