The sick and twisted servants of the evil Lord Voldemort are acting more openly, to the point where the non-magical world has started to feel their presence. Inside the walls of Hogwarts school for wizards a new term gets underway and the students are more concerned about burgeoning hormones than dark magic. There is a new potions master, Horace Slughorn, whom headmaster Dumbledore tells Harry is crucial to finding a way to destroy Voldemort. There is a memory, an altered memory, that holds the key and Harry must befriend Slughorn in order to learn the secret.

HARRY POTTER AND THE HALF-BLOOD PRINCE is the sixth book and film in the series and it makes absolutely attempt to bring anyone who hasn't been following the story up to speed. This is not so much a film as another episode in a mini-series, but writ large for the cinema screen. It starts where HARRY POTTER AND THE ORDER OF THE PHOENIX finished and hits the ground running. If this is your first Potter film then chances are you won't be able to follow who all these people are, what their significance is and how they all got to where they are in the story.

For those that have been paying attention, though, this film pays dividends on that interest. From the very outset it looks absolutely gorgeous with sweeping, gothic, epic camera moves, colour and landscapes. Eyecandy abounds all over the place and the only reason that you don't spend the whole time with a mouth open at the beauty of it all is because the plot and characters refuse to be overwhelmed by any of this.

The plot, actually, is very simple with Harry having to get the secret from Slughorn and there being a bit of interest between the opposite sexes going on, but there are also side stories such as Malfoy's mission from Voldemort, Snape's unbreakeable vow and Ron's ascent to quidditch popularity. Most of these are underbaked, relying on the fact that the audience know what is going on. Why Snape should make such a vow is never explained and the whole quidditch episode could have been excised without any great loss except that Harry Potter without a game of quidditch is like James Bond without a gun.

This is all about the characters and the young actors in the central trio of Harry, Ron and Hermione have all proven to be up to the task at hand. Supporting them, Michael Gambon makes a delightfully scatty, but smart nonetheless Dumbledore and Alan Rickman's slimy Snape comes into his own. Joining the team is Jim Broadbent as Professor Slughorn, a fairly pathetic creation whose relationships with his students might have caused concern in any other film series.

There is then a burst of action towards the end as the secret is learned, a trip is taken and a great loss is suffered. All of this is handled with aplomb by returning director David Yates, not quite managing to wring as much pathos out of the final tragedy as he might, but setting up the two part finale with some style.

If you're new to Harry Potter then go back to the start and catch up, but if you've been along for the journey then this is a great continuation.

Trailer