U.K. novelist Darren Shan's hugely popular, twelve-book series about an ordinary adolescent who discovers his extraordinary destiny at a macabre traveling show makes its first (and probably last) screen appearance in Cirque du Freak: The Vampire's Assistant, a colossal bore of a teen fantasy movie.

Polite, blandly attractive Darren Shan (Chris Massoglia) is that kid everyone knew in high school: Smart but not too smart, nice without being a wimp, pleasant company in the cafeteria and totally forgettable. He's the kid whose yearbook photo scarcely registers a year after graduation. His best friend, Steve (Josh Hutcherson), is a whole different story: Petty troublemaker par excellence, "future underachiever of America" is just about tattooed on his forehead. Darren's straight-arrow parents naturally think Steve's a bad influence and ground Darren after he and Steve get caught in an act of minor vandalism. But when the Cirque du Freak comes to town for a one-night-only engagement, Darren has to choose: Stay in his room, or sneak out and join Steve for a night of forbidden delights.

It will come as no surprise to anyone familiar with the conventions of teen fiction -- especially teen fiction awash in vampires, werewolves, bearded ladies, lizard boys, cogitating spiders and sorcerers -- that Darren's small act of defiance has far-reaching consequences. A day after their trip to the Cirque, Steve lies dying and Darren has made a Faustian bargain with the Cirque's resident vampire, centuries-old Larten Crepsley (John C. Reilly): If Crepsley will cure Steve, Darren will become his assistant, even though that means abandoning his family, faking his own death and becoming "half vampire" (they can go out during the day, which assists with the assisting). Worse still, Darren has picked an especially unpropitious time to join the world of the undead: There's a war brewing between civilized vampires like Crepsley, who keep their bloodlust under control and live alongside humans, and the Vampaneze, who revel in terror, torture and slaughter. Inevitably Steve and Darren wind on opposite sides of the simmering conflict.

If Cirque du Freak has one-tenth the devilish style of its opening credits, an animated series of spidery silhouettes that evoke an elegantly sinister world of gnarled trees, glowing eyes, skittering creepy-crawlies and great gaping mouths, it would be a thoroughly watchable exercise in spooky, not-too-graphic fantasy. But no such luck. Director Paul Weitz is partly to blame; in movies like About a Boy he demonstrated a carefully nuanced understanding of character that's nowhere in evidence here. But the real problem is that the screenplay seems to have been adapted by committee -- there's none of the quirky specificity that makes, say, the Harry Potter movies so engaging -- and the casting is ghastly. John C. Reilly is a fine actor who bears an unfortunate resemblance to Mr. Potato Head, and vampires -- good and bad alike -- are all about sex appeal, of which Mr. Potato Head has none. Salma Hayek, who sports a beard that can grow and retract at will, is wasted in what amounts to a bit part. Same goes for Willem Dafoe and Jane Krakowski, while the affable Massoglia is too insipid to ground a coming-of-age story with such dark underpinnings, no matter how muted. He is, however, perfectly suited to Disney-quality life lessons like, "It's not about what you are; it's about who you are," a bit of pre-packaged wisdom so trite, it's repeated twice.

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