(Herald rating: * * * * )

Newsflash: Sirius Black has escaped from Azkaban Prison. Sirius (Gary Oldman), for those whose memory of the events of 14 or 15 years, two books and a couple of blockbuster movies ago is somewhat hazy, was part of the gang when Voldemort killed Harry Potter's parents. Now he might be on the way to Hogwarts to kill Harry (Daniel Radcliffe)

Harry has innocently returned from another wonderful family Christmas to hook up with Ron and Hermione (Rupert Grint and Emma Watson) and the unusual array of new teachers, such as the sinister Professor Lupin (David Thewlis), who teaches protection against the dark arts, and daffy Professor Sybil Trelawney (Emma Thompson), who looks into Harry's cuppa and doesn't like what she sees in the tealeaves.

Perhaps we should include Michael Gambon, who takes over the late Richard Harris' robes and beard as Dumbledore. Nothing much has changed about Hagrid (Robbie Coltrane) apart from a new beast, a hippogriff - half bird, half horse - named Buckbeak.

The new director, Alfonso Cuaron, best known for Great Expectations and Y Tu Mama Tambien, has to change tack from the first two films. For one, his actors are noticeably older and have a little more difficulty in getting away with the innocence of their previous outings. Ditto, the story is far darker.

It will be interesting to see where the director of the next episode, the transatlantically inclined Englishman Mike Newell, takes the chapter about the Goblet of Fire, given his history with the Young Indiana Jones.

So, just as the young wizards are growing up, so is the audience for the series. This is quite definitely a movie for older teenagers rather than the all-in-the-family feeling of the first two, and Cuaron's handling of the task is a touch awkward, ponderous even.

The DVD features five "unfinished" scenes that add little to the exercise; there are some interesting cast and crew interviews (particularly Lenny Henry and Oldman). J. K. Rowling reveals that the story evolved from a childhood nightmare in Creating The Vision, while Cuaron indicates he might have had a similar experience as he tried to keep the creator satisfied when filming her books. After an exhaustive tour of the visuals, design and production, there are several interactive games for all ages.