HARRY POTTER AND THE HALF-BLOOD PRINCE   * * * *
Cert 12A, 153 mins
The late-teen Harry Potter stars have now spent half their school age lives working on bringing the boy wizard to life on the silver screen.

Testament to their energy, patience, talent and good fortune, The Half-Blood Prince is worthy of the continued effort which is surely as rewarding as it must be frustrating in equal measure.

All of the lead stars, Daniel Radcliffe (Harry Potter), Rupert Grint (Ron Weasley) and Emily Watson (Hermione Granger) are at an age where, in normal life, they would be spreading their anonymous wings on new adventures.

Going off to university. Taking a gap year. Starting a career.

Yet they remain willing captives in an astonishing teenage odyssey that’s still maturing.

And one that won’t conclude until The Deathly Hallows Part II is released on July 15, 2011, eight months after Part I’s expected arrival on November 19, 2010.

The good news for viewers is that both of these remaining instalments, adapted from JK Rowling’s seventh and final book, are being directed by St Helens-born David Yates.

Having most notably directed half a dozen episodes of the TV series State of Play, it seemed as if he was finding his feet in cinemas with Harry’s fifth adventure, The Order of the Phoenix.

Released two years ago this week, it will be the only Potter movie not to have been written by Steve Kloves, an earlier Oscar nominee for the Michael Douglas film, Wonder Boys.

But The Half-Blood Prince is clear evidence that Klove and Yates are the team to give the franchise a barnstorming finish, one which can finally begin to give The Lord of the Rings’ more focused, spiritual journey a run for its money.

In a series which has sometimes struggled to maintain momentum because of the well-intentioned efforts required to cram too much in, the sixth movie is a self-sustaining quality drama first and foremost.

Feeling much less like a showcase for guest star actors, or a laboratory for special effects designers, it has some terrific performances. Most notably Michael Gambon as Prof Albus Dumbledore and Jim Broadbent as Hogwarts’ newly-arrived potions master, Prof Horace Slughorn, who could be the key to explaining Lord Voldemort’s background.

Played here as the young Tom Riddle by teenage actor Frank Dillane, the origins of evil in one so young give the film a fascinating undercurrent ready for Ralph Fiennes’ future return.

Meanwhile, Radcliffe (20 next week), Watson (19) and Grint (18) are all affected by the wonders of teenage hormones as various will-they, should-they relationships come in to play with characters like Lavender Brown (Jessie Cave), Ginny Weasley (Bonnie Wright), Luna Lovegood (Evanna Lynch) and Cormac McLaggen (Freddie Stroma).

Add the effects of Horace’s potions and we really are entering a grown-up world, one where performance-enhancing substances are seen to have positive, negative and even placebo effects.

As the white-bearded Dumbledore tells Harry: ‘You need a shave my friend... at times I forget how much you’ve grown’.

Save for Harry’s face being regrettably stamped on by misled bad boy Draco Malfoy (Tom Felton), this is a relatively gentle film compared with modern 12As like Star Trek, Transformers 2 and Terminator 4. But, make no mistake, The Half-Blood Prince still has its dark moments and one jump-out-of-your-seat highlight.

A running time of 153 minutes plus ads and trailers is in itself reason enough to keep fidgets under the age of nine firmly at home (Vue Star City is running some adults-only screenings if you want to make sure).

The cinematography by Bruno Delbonnel, who won Oscar nominations for A Very Long Engagement and Amelie, is a wonderfully-rich mixture of light and dark hues.

Augmented by the sharper contrast of some black and white flashbacks, one can imagine the Boris Karloffs and Bella Lugosis of the heavens looking down and recognising something of their own dark arts in this picture. Though the airborne game of Quidditch still hasn’t quite been fully mastered – the broomsticks jerk a little too much compared with how birds really fly – the special effects scale new heights.

Anyone watching this on the West Midlands’ biggest screen at IMAX, Millennium Point, will have the added bonus of enjoying the first 12 minutes in IMAX 3D. But, having already seen both versions, the rapid-fire journey through the streets of London and the destruction of the Millennium Bridge works just as well in 2D, such is the attention to detail with the effects.

The icing on the cake is the score by Nicholas Hooper (The Order of the Phoenix). Building on the twice Oscar-nominated work of John Williams, it feels as if it has been written in the context of the film, which is by no means always the case in Hollywood (see Troy, for example).

Come the finale, Hermione has some pertinent advice for The Chosen One, saying: ‘I’ve always admired your courage, Harry, but sometimes you can be really thick’.

After Dumbledore has predicted that he’s going to be asking ‘too much of him’, Hermione will, it seems, ensure that Harry’s most dangerous future journey will not be alone.

For now, with drama, action and comedy coming together in harmony in The Half-Blood Prince, and all of the extra crafts complimenting every scene, the Harry Potter franchise is finally ready to come of age.

It really is a kind of magic.