When you come out of Paul Weitz's comic horror film "Cirque du Freak: The Vampire's Assistant," you don't feel like you've watched a real movie.

It's more like the pilot episode of a new teen-centric TV show where the main characters get introduced and all the ground work gets laid for the plots of future episodes.

Actually, I really liked the first half of "Vampire's Assistant," back when it was called Ray Bradbury's "Something Wicked This Way Comes," about two best pals - complete opposites - who sneak off to see a mysterious traveling circus and wind up in the clutches of evil.

The opposite best pals in "Vampire's Assistant" are high school students Darren (a blandly benign Chris Massoglia), a goodie-two-shoes kid who earns top grades, and Steve (an edgy Josh Hutcherson), a disgruntled, troublemaking rebel from a broken home.

Steve, who's such a fervid vampire fan that he wants to become one, goes nuts when he sees a flier promoting a freak show in town. He drags Darren to it, and in the middle of the program - a special-effects enhanced parade of shocking physical deformities - swears that the flame-haired emcee is a vampire from one of his books.

Indeed he is.

Larten Crepsley (played pitch perfect by Chicago's own John C. Reilly) looks more like Carrot Top than Count Dracula. But he's a vampire, and he agrees to save Steve from a fatal spider bite administered by his pet arachnid Octa if the timid Darren will serve as his half-vampire assistant.

That deal done, the best pals wind up on opposite sides of another one of those bizarre horror film civil wars between monster factions, here between the nice vampires who suck human blood without killing the hosts, and the "vampaneze" undead who enjoy violence and slaughter.

"Vampire's Assistant" begins auspiciously enough with taut dramatic tension, J. Michael Muro's well-composed camera work and Stephen Trask's subtle, exciting music, but it bogs down into generic conventions the longer it plays.

Weitz and Brian Helgeland reportedly adapted this movie from three of Darren Shan's 12 "Cirque du Freak" books, and they commit a classic mistake by having Darren (the hero) narrate the movie as a first-person experience, which makes no sense the moment events unfold that Darren couldn't possibly know about.

Then, just when we expect some profound epiphanies from Darren after he fully embraces his new alternate deathstyle, "Vampire's Assistant" practically turns into a Walt Disney message movie.

"It's not about what you are," coos Rebecca the Monkey Girl (Jessica Carlson), alias Darren's obligatory romantic interest, "It's about who you are!"

Thanks for delivering the movie's moral, Monkey Girl!

Michael Cerveris, resembling Mr. Clean's evil twin, plays Mr. Tiny, the enigmatic manipulator who entices angry Steve to take up the vampaneze cause and maybe break the vampire peace that has existed for hundreds of years.

"Vampire's Assistant" has a crypt full of name actors utterly wasted in frivolous roles. Willem Dafoe leads the pack as Gavner Purl, Larten's friend with greasy hair and a pathetic John Waters mustache.

Even the curvaceous Salma Hayek has a mustache. She plays Madame Truska, a busty clairvoyant who grows a full Abraham Lincoln beard every time Larten kisses her.

Other wasted talents include Ken Watanabe as the freak show manager Mr. Tall, and "Almost Famous" star Patrick Fugit as a would-be-rocker known as Evra the Snake Boy.

Note for die-hard movie trivia fans: Listen for the line "You're one of us!," a reference to a famous scene from Todd Browning's classic 1932 horror film "Freaks," starring actual sideshow performers.