THE golden age of innocence at Hogwarts is over. Puberty has sunk its claws into Harry Potter and sexual jealousy haunts his friends.

The 14-year-old hero has sprouted from a bespectacled geek into a shameless poster boy. And his loyal chums — Ron (Rupert Grint), and Herminone (Emma Watson) — have followed suit. Adolescence is Harry’s new foe. And it brings the kind of challenges that most parents hate. The young wizards are much more comfortable wearing grungy jeans than capes; and their tastes run to muddy Glastonbury rather than tea and cakes.

The hairstyles are longer and the teenage hormones ping off the walls like snooker balls. The irony is that our valiant trio are more terrified of securing a date for the Yule Ball at Hogwarts than they are tackling the latest dastardly threat to their potty lifestyle. It seems like only yesterday when the three wizardy sprigs were battling giant spiders and cracking deadly conspiracies in the girls’ toilets. That knowing comedy keeps this episode sharp.

Mike Newell, a self-confessed “computer generated image” novice, is the first British director to pick up the baton in the Potter franchise. His considerable triumph is to keep the thrills up to exhilarating scratch. One of the perennial joys of J. K. Rowling’s addictive series is the ability to generate ever spookier shades of evil. Here, the fear comes in the shape of scary dragons, a poisonous vision of Lord Voldemort. Ralph Fiennes’ whispy ghost is an ice age chillier than the previous incumbents.

The plot hinges on a famous Tri-Wizard Tournament. It’s an international wand-flexing competition starring the shapely girls from France, the Beauxbatons; and the butch Durmstrangs from Bulgaria.

What’s fresh about the Goblet of Fire is the intriguing tension between the feeble and the strong. This has always been Rowling’s tug of war. The playground duels between Harry and his peers are as bitter as ever, but there’s a delicious sense of anarchy about boarding school life. For the first time we sense what makes Harry tick under pressure.

There are plenty of old familiar staples for fans: the unsporting cut-and-thrust of a Quidditch World Cup; a maze that stretches for ever; and a mission impossible at the bottom of a lake. The Dursleys are sadly missing. But one can’t have everything. The red-herrings are worth hanging on a wall. Brendan Gleeson’s Mad-Eye Moody is the latest loose cannon on the staff. It’s impossible to fault the shades; I’d like to bid for the marble eyeball.