ALL JAMIE WANTS to do is take mescaline under the stars.

He's been reading The Doors of Perception, and he came to Chile determined to find out what Huxley was on about. It's easy to see why the idea of opening up perceptual doors has taken such a strong hold with Jamie—he is one uptight, closed-off motherfucker.

One night at a party, Jamie (intelligently played, against type, by Michael Cera) meets a girl who goes by "Crystal Fairy" (Gaby Hoffmann! The little girl who choked on a hot dog in Field of Dreams!). A fellow American, she's dancing like an idiot and he's standing against the wall with his arms crossed, which is a perfectly accurate distillation of their characters and relationship. Drunk and high, he invites her on the road trip he's got planned for the next day: He and three Chilean friends, brothers Champa (Juan Andrés Silva), Lel (José Miguel Silva), and Pilo (Agustín Silva), are going in search of the San Pedro cactus, which they plan to distill into mescaline and drink on the beach.

The next day, Jamie doesn't remember making the invitation—but Crystal Fairy remembers, and she tags along even though Jamie makes it clear that inviting her was a coke-addled mistake.

Crystal Fairy is a case of hipster vs. hippie: Jamie, controlled and controlling, is inflexible and dictatorial in his pursuit of fun, while Crystal Fairy is kind and embarrassing and uninhibited. (After seeing her naked, the boys take to calling her "Crystal Hairy," for reasons that are very, very obvious.) The three brothers serve as bemused witnesses, as uncertain as the audience as to which is more insufferable. But while its main characters aren't particularly likeable, they're also incredibly well-drawn and recognizable types, and the film functions beautifully as a two-pronged personality study of two ugly Americans looking for what they think they need, far from home.