"Nick and Norah's Infinite Playlist": When lead couple are alone, all else is forgiven

The modern world of teenage romance is a complicated place. Are you a hipster, an emo, a mean girl, a straightedge? These labels are all important when it comes to potential hookups between the pretty young specimens who inhabit the fantasyland of "Nick and Norah's Infinite Playlist."

Though it fails as a believable account of lives actually lived by contemporary teenagers, the movie is saved by the chemistry and charm of its two leads. As they scurry about the far reaches of New York over the course of one magical night, Michael Cera and Kat Dennings give the title characters enough of a spark to make the rest of the silly, exasperating story easier to take.

From their suburban New Jersey enclave, Nick and Norah are strangers to each other, but they venture into New York for the same reason: They're on the trail of a white-hot underground band that plays mysterious gigs advertised only by cryptic symbols. Their mutual connection is a self-absorbed siren named Tris (Alexis Dziena), who broke Nick's heart and is a petty irritant to Norah in the halls of a Catholic girls' school. Norah knows about Nick, thanks to the moony and meaningful mix CDs he still compiles for Tris. She tosses them away without listening, but Norah rescues them from the trash with romantic wonder about the sensitive boy who made them.

As Nick, Cera plays an appealing version of himself just as he did in "Juno," "Superbad" and "Arrested Development." It remains a good thing, and he should keep on doing it. Kat Dennings makes Norah just as real, with a beguiling offhand innocence that's sexy and intelligent.

As for the rest of the saga, there's not much reality or intellect to be found. The gangs of yammering 18-year-olds waltzing through the hottest clubs in Brooklyn and the East Village feel false and unconvincing. Played-for-laughs teenage binge drinking was never so unfunny. There's also a running gag about a wad of gum that's chewed over ad nauseam — literally.

Another of the movie's selling points is its supercool indie-rock soundtrack, which includes Vampire Weekend and Seattle's Band of Horses. The movie is best when Nick and Norah are alone with the music or each other.

Ted Fry: tedfry@hotmail.com