Sequels have a mixed history in Hollywood. While most critics regard The Bride of Frankenstein as far superior to the film that spawned it, many were quick to call Rocky II a remake rather than a follow-up.

In a lot of ways, movie sequels are much like traditional weddings: something old, something new, something borrowed and, in the case of Harry Potter & the Prisoner of Azkaban, definitely something blue.

As for the old, no Harry Potter film (this is the third) would be complete without the triumvirate -- Harry, Hermione and Ron -- played in The Prisoner by the tried-and-true trio of Daniel Radcliffe, Emma Watson and Rupert Grint. And there's Hogwarts, of course, the school for wizards- and witches-to-be, still headed by Albus Dumbledore (Michael Gambon, replacing Richard Harris, who died in 2002), with featured faculty Minerva McGonagall (Maggie Smith) and the slippery Severus Snape (Alan Rickman).

But there's a new prof in town, Professor Lupin (David Thewlis), and an old character, Rubeus Hagrid (Robbie Coltrane), with a new job -- professor -- and the task of introducing students to a new creature, Buckbeak, who's half bird, half horse and all trouble for those, like Draco Malfoy (Tom Felton), who don't take the time to cultivate its friendship.

There's also a new reason for Harry to be concerned about his future, should he have one: the prisoner (Gary Oldman) -- or should we say ex-prisoner, since he'd escaped Azkaban even before the credits rolled -- a wizard who allegedly turned over Harry's parents to the dark forces of Lord Voldemort, resulting in their untimely deaths. Now, word has it, he's looking for Harry.

To protect the school and, by extension, Harry, the Ministry of Magic has called in the Dementors, creatures so scary it's hard to believe they could possibly be on Harry's side -- or anyone's but their own. They've encircled Hogwarts, but aren't above entering its gates if they think their services are called for.

But more importantly -- for film reviewers, at least -- the Dementors point to what's really new in the Harry Potter films: the tone. Unlike Sorceror's Stone and Chamber of Secrets, in which Harry faced larger-than-life but palpable villains, in Prisoner, it's hard for Harry or us to figure out what he's fighting. That's accomplished in part by the portrayal of the Dementors as creatures who are part Wicked Witch of the West, part ghost and part vampire, with the apparent ability to suck the souls from anyone within eyeshot.

Adding to that eeriness are the sets, the settings and the cinematography. Stone and Chamber had the look of Charles Dickens' London. In Prisoner, Hogwarts still has its castle appeal, but director Alfonso Cuaron and cinematographer Michael Seresin set it in the middle of a mountainous nowhere, ratcheting up its sense of isolation and providing some of the most eye-shattering shots since Lord of the Rings.

The camera makes its point, too. It seems it never stops moving, following its characters everywhere, but leaving viewers without a stable perspective.

And then there are the sets. They move almost as much as the camera does, especially in the halls of Hogwarts, where the ever-swinging, ever-circling clock mechanism seems to find its way into nearly every scene.

Finally, there's the color scheme. From the rain-soaked train that takes Harry to Hogwarts to the snow-covered hills around the school and the fog-shrouded forests in which Harry and Hermione take refuge, blue is clearly the color of choice.

Add to that the theme -- apparently borrowed from The Lion King -- of the father reaching out from his grave in his son's moment of peril -- and you have the thing that distinguishes Prisoner from its predecessors: its overarching moodiness.

Prisoner doesn't have to shock you: You're scared just thinking about what might be out there.

That said, there are some problems with Cuaron's piece of Pottery. One is that the film moves so fast it's not always easy to keep up with the plot, which often seems to be delivered on the fly, and another is that the ending doesn't seem to tie things up satisfactorily or give us much indication of where Harry's headed next.

Still, Prisoner pushes Potter into new ground, and very fertile ground. A remake it's not. A reimagining it is. And a great one.

- Rambles
written by Miles O'Dometer
published 8 January 2005