With an offhand precision that suggests he might prove to be one of his generation's major actors, Michael Cera lays bare two specific human weaknesses in writer-director Sebastián Silva's altered-states/group-dynamics road drama Crystal Fairy—weaknesses you'll likely recognize from life rather than from other movies. The first is the pushy, wheedling neediness of the people who crave drugs too much. Not the full-on junkies, but the friends you worry will become junkies, the ones who, when not high, are trying to find ways to suggest everyone get high, and when high only want to discuss whether they're high enough.

Even at a house party in Santiago, Chile, where everyone else speaks a language he can't be bothered to learn, Jamie affects an itchy authority, an expertise on the quality of the local blow and a put-on assumption that he is so cool and commanding that it would be a kindness of him to interrupt the dancing of a blissed-out hippie girl to tell her that she's embarrassing herself. Then, once this outsider playing insider has schooled that other outsider, it's off to do the last dregs of that coke—even if nobody else wants to.

Spouting facts cribbed from the Internet and Aldous Huxley's The Doors of Perception, Jamie has goaded his Chilean host, Champa (Juan Andrés Silva), and Champa's two brothers (José Miguel Silva and Agustín Silva) into journeying out of town to track down a psychotropic cactus for boiling and ingesting on a magnificent beach. Problem is, at that party, the coke and Jamie's need to be liked came together like vinegar and baking soda, setting off a foaming volcano of kindness. That dancing hippie girl (the stellar Gaby Hoffmann) turned out to be the first American he had seen in Chile—and at some point he invited her to join in on the cactus hunt. Worse, she accepted. And even worse than that, she calls herself Crystal Fairy, chides the boys for scarfing junk food, and rattles on about chakras and healing.

That brings us to the second weakness, one we see flower as the film and road trip glide on. The one thing passive-aggressive Jamie seems to love as much as drugs is talking shit about people the second they're out of earshot, especially Crystal Fairy. With apologetic giggles, and a condescending sense that the other American on the trip must be his responsibility, Jamie crabs to the brothers about how awful she is, how if they all agree she's ruining the trip he's up for taking care of it—ditching her someplace, even. The brothers nod, laugh, sometimes mount a minor defense: “Fuck, it's Crystal Fairy,” they say, as if that explains everything.

It does, actually, although Jamie can't see it. She is just as insecure as he is, sometimes just as hard to take, and always as committed to playing the role of a confident authority she might not get away with back in the States. Early on, she parades nude before the four boys, feigning a casualness as tricked-up and pushy as Jamie's narco know-it-all-ism.

The Americans' awfulness is minor and redeemable, fortunately, so the trip is never a drag. The film is often beautiful and appealingly light. Every clear-eyed insight into why pushy people insist on pushing is matched by loose ensemble humor and lyric reveries: the troubles of acquiring a magic drug cactus; pee breaks on other-planet desertscapes; scenes of the boys, blissfully wasted, splashing in the surf. Rather than attempt to re-create drug experiences with lenses and effects, Silva trusts the actors with suggesting the surges and manias of the characters' trips. That risk yields some of the most finely realized drug scenes in cinema, sequences that glance up against the awe and awfulness that hallucinogens unfurl. Cera's a pleasure even as Jamie's antsiness grows more abrasive. His hair is longer than usual, a curly halo, and that boy's face of his is now stretched over a man's skull. There's a tender radiance to him here, and some string-bean clowning; at times, especially when he's playing a beatific high, he looks for all the world like Harpo Marx.

Silva has mastered a relativistic empathy, flushing into us both the feeling of being insecure abroad and what it's like for the Chileans to have to hang with this pair. The brothers' ongoing discussion of the narcissistic leads, helpfully subtitled, often punctures the interior drama, which only rarely bursts through so strongly that the characters have to acknowledge it. Jamie and Crystal Fairy know that to upset their easygoing chaperones would ruin everything—the weekend, the drug trip and, most important, the Americans' individual conceptions of themselves as fully formed and above it all. You may not care about drugs, or the adventures of white kids abroad, but by the time Crystal Fairy hits its low-key, truly moving reconciliation, you'll likely care about its people. You'll probably even recognize their best and worst aspects—again, not from the movies but from those friends and co-workers you still enjoy even when they verge upon being assholes. If so, see it again and lug them along. Maybe they'll learn something.

Follow @VoiceFilmClub

Advertising disclosure: We may receive compensation for some of the links in our stories. Thank you for supporting LA Weekly and our advertisers.