OVER THE SCREECHING din of the shack, Radcliffe repeatedly shouts, "You betrayed my parents! You're the reason they're dead!" During a break in the action, though, he twirls his wand genially like a baton. Wait, sorry, it's not a baton-that'd be so 12 years old. Radcliffe, who turned 14 last week, is bashing the air feverishly. He's doing a drum solo.

To prepare for the older, bolder "Harry Potter and the Prisoner of Azkaban," Radcliffe has been listening to the Sex Pistols-which broke up 11 years before he was born-as well as edgy new acts like the Strokes and the Dandy Warhols. He's also watching Francois Truffaut ("The 400 Blows") and Vittorio De Sica ("The Bicycle Thief") to get a handle on Harry's "feelings of hopelessness." Yes, "Azkaban" is the puberty movie in the Potter franchise-the one, says Emma Watson, who plays Hermione, in which "all those lovely, lovely hormones start coming out." How will the movie reflect the changes afoot? "Lots of sex," says Alfonso Cuaron, the Mexican director who's taken over the reins of the series from Chris Columbus. "Lots of nudity. And lots of sex." Relax, he's joking. But Cuaron notes that his teenage cast is coming of age just as the characters are, and that there's, uh, pollen in the air. "You just have to let it flow," he says. "You don't need to encourage it. You allow it to be. And believe me, they have a lot of it." Watson, who's 13, has a sign on her dressing-room door that reads BEWARE: BABE INSIDE.