''Cry Wolf" is a sheep in wolf's clothing: a mystery-thriller disguised as a routine dice-and-slice teen horror flick. Give it points for trying something different -- and then take them back for botching the job. This is, after all, a movie in which nubile young women say things like, ''I'm all congested from crying. I'm going to take a shower; the steam might help."
After an opening scene in which a terrified girl is butchered in a nighttime forest -- a sequence contractually stipulated by California state law to appear in all movies marketed to teenagers -- the setting shifts to nearby Westlake Preparatory Academy. The school resembles a kinder, gentler Hogwarts, and the students are all rich, bored, and in their mid-to-late 20s.
New kid Owen (young UK heartthrob Julian Morris, obliging Gary Cole to adopt a British accent as his distant dad) arrives at Westlake on double secret probation from other schools and quickly falls in with the bad kids. And a multi-culti group they are: punker Randall (Jesse Janzen), Asian-American Regina (Kristy Wu), Latina hottie Mercedes (Sandra McCoy), Afro-Am Lewis (Paul James), Graham the nerd (Ethan Cohn), and Owen's roommate Tom (Jared Padalecki), who hails from the country of Biganddumb. Owen has eyes only for Dodger (Lindy Booth, ''Dawn of the Dead"), a slim bottle-redhead with a penchant for mind games.
Said games begin with an after-hours round of ''Murder" (some of you know it as ''Mafia") in the school chapel, then turn ambitious when the group decides to freak out the entire student body. Taking the recent murder as a starting point, they concoct a serial killer, ''The Wolf," and send out a mass e-mail that details his past crimes.
Wouldn't you know it? The Wolf turns out to be real, and he prefers to be his own publicist.
At least, that's how it appears from the spooky instant messages that keep popping up on Owen's computer and from the ''gotcha" shots of a hulking figure in an orange ski mask (who may be a Mexican wrestler who's lost his way; it's not clear). But even as the hero's friends start disappearing faster than you can say ''Ten Little Diverse Ethnic Representatives," ''Cry Wolf" is suspiciously light on gore and dismemberment. Is the PG-13 rating to blame, or is it something more . . . sinister? Either way, hardened fans of movie splatter may be tossing their Big Gulps at the screen in contempt.
Director Jeff Wadlow tries to goose the proceedings with a few tricky camera moves that will go straight to his clip reel, and, to his credit, he and cowriter Beau Bauman throw enough curveballs to keep the target audience guessing. (Seasoned veterans, on the other hand, will be able to spot the killer within 10 minutes.) More amusing is the way technology blows up in the characters' faces, from those threatening IMs to a cellphone that inadvertently takes a picture of the killer. But perhaps people too stupid to remove their iPod headphones while investigating scary noises deserve whatever they get.
For grown-ups, ''Cry Wolf" is notable mostly for the appearances of rocker Jon Bon Jovi as a shifty journalism teacher and actress/playwright/performance artist Anna Deavere Smith as the school headmistress. She's not the first MacArthur Foundation genius to appear in a junky B-flick -- John Sayles's appearance in 1978's ''Piranha" gets the nod for that -- but she's certainly the most shame-free.
Ty Burr can be reached at firstname.lastname@example.org.