Harry's greatest challenge

In his spectacular summation of JK Rowling's tome, Michael Newell leaves quite a lot out - and puts quite a bit in. Like sex, for example, and memories of his own fraught school days.

But don't worry Rowling is in no way undermined and certainly she's never had so many CGI effects sprayed over her words.

If Alfonso Cuarón brought cinematic style to the third film, Newell, the series' first British director, goes for character and a bit of psychological insight.

Harry (Daniel Radcliffe) and his friends Ron (Rupert Grint) and Hermione (Emma Watson) have never seemed more like real teens fighting the difficult battle grown-up.

The plot, as those legions who have read the book will already know, concerns Harry's fourth year at Hogwarts School of Witchcraft and Wizardry.

Overseen by Michael Gambon's impressive version of Dumbledore, he must compete in the dangerous Tri-wizard Tournament, which pits one candidate from each of the three most prestigious wizarding schools against each other.

The sexy girls of Beauxbatons and the dangerous-looking boys of Durmstrang Academy come along to spectate as, in a fateful twist, Hogwarts is represented by both Harry and golden boy Diggory (Robert Pattinson).

For Harry, dealing with dragons, merpeople and grindylows is difficult enough. But inviting Cho Chang (Katie Leung) to the Yule Ball is worse. And then there's the sudden appearance of the vile Lord Voldemort (Ralph Fiennes) to contend with. Newell gives us all the wizardry we could want and tries hard, and often successfully, to point up the characters.

He manages to elicit performances from Radcliffe, Grint and Watson that dig a little deeper than previously. Grint is the best of them, surely a star in the making.

The rest of the cast, with one or two exceptions, try hard not to parody the proceedings with over-the-top derring-do.