LONDON — In "Harry Potter and the Goblet of Fire," the teenage wizard faces new terrors. A face-to-face encounter with his nemesis, the evil Lord Voldemort, for one. Girls, for another. And, still fresh in the mind of 16-year-old star Daniel Radcliffe — ballroom dancing.

"I really wanted to be good at it," Radcliffe said of the scene in which Harry dances at the Hogwarts School of Witchcraft and Wizardry Yule Ball.

In the end, he said, director Mike Newell "very kindly didn't show anything below my waist. You never see my feet move."

Radcliffe's down-to-earth charm, on display at a London press conference to celebrate the film's release, is key to the success of the Potter films, which have become a lucrative franchise since "Harry Potter and the Sorcerer's Stone" was released in 2001.

Radcliffe was 11 when he first wore Harry's trademark spectacles and lightning-shaped scar. Five years later, he's an assured and articulate actor who enthuses about his favorite bands — The Libertines, Hard-Fi and Louis XIV all get the nod — and gently coaxes his co-stars.

Producers describe "Goblet of Fire," in theaters Friday, as the darkest Potter film yet. Harry must face a confrontation with Voldemort, the evil warlock who killed his parents and who returns to human form — in the shape of Ralph Fiennes — bent on destroying the young wizard.

Charting Harry's fourth year as a trainee wizard at Hogwarts, the film has plenty of magical set pieces to delight fans of J.K. Rowling's saga. There are airborne acrobatics at the Quidditch World Cup, and the Triwizard Tournament — a perilous contest that sees Harry face off against a fearsome Hungarian Horntail dragon.

As well as Fiennes, new cast members include Brendan Gleeson ("Troy," "Cold Mountain") as Potter's new Defense Against the Dark Arts teacher, the fearsome Mad-Eye Moody; and Miranda Richardson ("The Crying Game," "Sleepy Hollow") as poisonous gossip columnist Rita Skeeter.

The movie also introduces new students to Hogwarts, including Stanislav Ianevski as Bulgarian Quidditch star Viktor Krum, French actress Clemence Poesy as the heart-fluttering visiting student Fleur Delacour and Scottish schoolgirl Katie Leung as Harry's love interest, Cho Chang.

British director Newell ("Four Weddings and a Funeral," "Donnie Brasco") said he was nervous about condensing Rowling's 640-page book into his first Potter film.

"The book's as big as a house brick, and I was very unsure quite how one would attack it," said Newell, who follows American Chris Columbus and Mexican Alfonso Cuaron at the Potter helm.

One idea was to split it into two films. But Newell said he eventually found the key to the story — "it was a thriller."

"As soon as I could see that, I felt that I could stay true to the book and at the same time keep the length down," Newell said.

With the films now more than halfway through Rowling's planned seven-book series — the sixth volume, "Harry Potter and the Half-Blood Prince," was released earlier this year — budding romance is a new development for the teenage Harry and his friends Ron and Hermione.

Inevitably, Radcliffe and his co-stars Emma Watson, 15, and Rupert Grint, 17, faced questions about their own love lives. They deflected them with good grace.

"I'm learning to drive at the moment," Grint said, "so that's taking all my time."