Starring Alex Pettyfer and Dianna Agron. Rated PG.

The undeniable awesomeness of I Am Number Four is the way the aliens-on-Earth flick has something for almost everyone. Riot nrrrds will thrill to the jocks at high school getting exactly what’s coming to them. Those who believe the truth is out there will like how the smartly paced teen movie suggests that we’re not alone.

And hormonally ravaged teenagers will learn that, sometimes, um, pleasuring oneself leads to more than hairy palms. When high-school dreamboat John Smith (a convincingly brooding Alex Pettyfer) officially starts to become a man, his hands light up like Texas on the Fourth of July.

That makes it difficult for Smith keep his real identity a secret: forget being just another student in small-town Ohio; he’s Number 4, one of nine aliens who’ve escaped to Earth after their home planet Lorien was destroyed. Numbers 1, 2, and 3 have been assassinated by roving Mogadorians, a tattooed race that combines the ugliest bits of Vinnie Jones, Mr. Clean, and Kerry King of Slayer.

Despite the odd spotty performance (Timothy Olyphant is off-puttingly wooden as Smith’s guardian, Henri), I Am Number Four knocks it out of the park. Director D. J. Caruso deserves particular credit for taking the time to make his young characters interesting; consider how Number 4’s number-one girl, Sarah (Glee’s Dianna Agron), is both a homecoming princess and an unhappy misfit with a thing for old-school photography.

When the inevitable showdown starts, the kids in I Am Number Four completely kick ass, with the girls bringing just as much crowd-pleasing viciousness as the boys. This franchise-in-the-making is ostensibly geared to the Twilight set, but offering up teenage alienation, aliens-out-of-water battles, nuclear-strength explosions, and enough angst to make Paxil stockholders giddy, it delivers something much, much more.