Though he must battle a spiny dragon, octopus-like creatures and fierce mermaids, Harry is almost equally bedeviled by the idea of his first dance.

In "Goblet of Fire," the young wizards are "much more complicated," says director Mike Newell, the first British filmmaker to direct a Potter movie. "In the first three films, their characters were defined by what they were up against: a werewolf, a basilisk, a dementor. But this time, the story is how they're developing as people. So the school's Yule Ball is a torture to Harry and Ron because they have to ask girls out, and they don't know how."

Harry (Daniel Radcliffe) will again face his mortal foe, Lord Voldemort (Ralph Fiennes). "Voldemort is an utterly malignant human creature, a lot more savage and cruel than any invented creature could be," Newell says. "Harry has to find the resources in himself to do battle with him."

The physical requirements were much tougher this time. "Goblet" is more of an action thriller than the previous three because it centers on an elaborate physical contest, the Tri-Wizard Tournament.

Radcliffe, now 15, had to learn to scuba-dive, then act underwater. "Just keeping your eyes open for a significant time is difficult," Newell says. "We couldn't do anything for more than 15 seconds at a time, which proved very complicated."

In another scene, he slides down a roof to battle a dragon. "It was pretty much a vertical drop of about 50 feet," Radcliffe says. "I was on a wire going so fast that my mind didn't have time to catch up with my body and go, 'Wow, I'm falling.' It was fun after the first take. But at the beginning, I was absolutely terrified."

For the climactic scene in which he hands over the body of a fellow contestant to the boy's father, Radcliffe says, "I had to tap into emotions that I personally never felt, that most people have never felt. Because they were challenging, it does make them fun." But Radcliffe says the character's death is "not gory or graphic. There's not any blood at all."

His run doesn't end with "The Goblet of Fire."

Radcliffe has said he will definitely be back as Harry in the fifth movie, "Harry Potter and the Order of the Phoenix," which starts filming next year.

However, Radcliffe has not gone back and watched the earlier films. "I kind of contemplated watching the first; then I decided I sort of valued my sanity a little too much. I think it would be far too strange, and I would be self-conscious about what I do now."