15 years ago no-one, least of all Hollywood, would have dreamt the world would become overwhelmingly preoccupied with the progressive adventures of a four-eyed schoolboy wizard, that his creator would have wealth that rivalled the Queen of England’s and that the theatre knights and dames of that realm, Maggie Smith and Michael Gambon among them, would play the supporting roles in the ongoing films of the books which already run to a greater length than Wagner’s Ring Cycle and are made with the slavish fidelity normally reserved for Shakespeare or Pride and Prejudice.

Well, Harry Potter’s an old story now. Yesterday L’Osservatore Romano declared that the new movie Harry Potter and The Half-Blood Prince was the best so far and gave the Vatican’s seal of approval for the element of sacrifice (this is the one where a beloved character takes a fall) and also declared that the emphasis on love and snogging (a big turn off for the primary ankle biters one would reckon) achieved the right kind of balance. Yesterday, too, a huge audience of Melbournians, including the attorney general Rob Hulls, risked swine flu to attend the 6:15 preview on the Imax screen at the Museum.

We donned our 3D glasses for the dizzying opening that made soaring scenes of mayhem in contemporary London look like the epic of the ages. Then we took them off and savoured the … er … more leisured pace of the rest of this epic.

Harry Potter and The Half-Blood Prince comes well after the time when anyone could edit JK Rowling. It’s very long, very episodic (with plenty of moony adolescent love interest) and then, in its last movement, all hell breaks loose with extraordinary scenes that involve Dumbledore (Michael Gambon), Snape (Alan Rickman) and that nasty youngster Draco Malfoy.

For much of its earlier exposition Half-Blood Prince is preoccupied with which bit of magical nastiness the Dark Lord, Voldemort, in his youthful incarnation as Tom Riddle, might or might not have managed to extort from Professor Slughorn. In the film, Professor Slughorn is played with great ripeness by Jim Broadbent, a man who knows how to milk a camp role (remember Baz Lurhmann’s Moulin Rouge?) and Tom Riddle is impersonated not by the serpentine Ralph Fiennes but by the gloriously named Hero Fiennes-Tiffin when he’s a creepy angelic looking eleven year old.

So how does it stand up? Well, at the end of the day the Harry Potter cycle is beyond criticism. The story that combines the juvenile charms of school hijinks with the war against the terror of black magic is simply the all-consuming fable we tell ourselves and with which we distract ourselves.

Umberto Eco is right that to understand a time you can ignore the high art but not the popular. Clive James has a point too when he says we should thank God Rowling is devoted to such a humane vision, that this mass cult isn’t, say, fascist.

The new film, like its predecessors, aims to be a palimpsest of the book. It is, in its way a pretty magnificent aide de memoire for the fifty million Harry diehards. I must say, though, that as someone who has listened to every word of Stephen Fry reading this book (which is the platonic idea of how to experience Harry Potter) the story only seemed intermittently familiar until its final riveting movement.

That’s largely because it’s so episodic that it actually has the material for a huge mini-series where the snogging and quidditch alternate with the armies marching by night, the deatheaters speeding like a vision of hell through Britain’s low sky.

A vision of the culture of the future perhaps, even longer Harry Potter. In the meantime, this one will keep the kids, though maybe not the olds, going. It can’t be a bad thing, though, that they get to see Dame Maggie as Professor McGonagall along with the now gorgeous Emma Watson as Hermione.

*Go to Crikey’s website where we review the reviews of the latest Harry Potter film.