Forget Superbad - the teen movie you need to see is Rocket Science, an alternately sweet, melancholy and very funny comedy about life on the high school debate team.

The movie is by documentarian Jeffrey Blitz, whose extraordinary Spellbound was similarly preoccupied with overachieving kids on the verge of collapsing beneath the weight of their own anxiety.

This new work may be fiction, but it feels just as honest and just as involving as a documentary.

The story focuses on three teens in New Jersey, all of them embroiled in the insanely competitive world of policy debate, where the key to victory is to talk two miles a minute while defending the most indefensible positions imaginable.

Plainsboro High's current champion is the legendary Ben Wekselbaum (Nicholas D'Agosto), a handsome, self-confident young man who, at the start of the movie, has a mysterious onstage meltdown and decides to drop out of debate altogether.

That collapse leaves his former partner, Ginny Ryerson (Anna Kendrick), scrambling to find a replacement.

With motives that may or may not be entirely pure, Ginny sets her sights on recruiting Hal Hefner (Reece Daniel Thompson), a painfully shy boy with a very severe stutter.

To say much more about Rocket Science would be to spoil one of its chief pleasures - namely, the plot that never quite goes in the direction you might expect.

Some of the early scenes in the film, which features an omniscient, third-person narrator, feel overly similar to the arch comedies of Wes Anderson, like Rushmore and The Royal Tenenbaums. But Blitz gradually drops the glib pose and deepens the emotions in the film until, by the end, you find yourself unexpectedly close to tears.

It helps that he's cast three splendid young actors to anchor the film. D'Agosto and Kendrick play a pair of smooth operators who have learned to mask their insecurities through bravado and performance. Thompson makes us feel the anguish of a lonely young man who, try as he might, can't seem to overcome his speech impediment.

They've given us the most complicated and original teenage characters we've seen in a movie in a very long time.