In this drug-addled dramedy, Michael Cera stars as a young entitled American jackass on a psychoactive cactus pilgrimage in the Chilean desert. Join him. No, seriously, do. Conceptually, Sebastián Silva’s scruffy little road movie sounds marginally insufferable, but that’s all the more reason for the relief and delight of discovering how nimbly dramatized and confidently directed it actually is. While eagerly en route to presumed transcendence, Cera’s character and his Chilean pals, played relaxedly by Silva brothers Juan Andrés, José Miguel, and Agustín, take a young woman into their midst, the vaguely imperious free spirit from whose name the movie takes its title. She’s note-perfectly played by Gaby Hoffmann, as an often-naked neo-hippie whose fixations include karmic cleansing and “good-energy pebbles” and, this taking place pre-2012, the impending Mayan End Times. Within the given context, Hoffmann seems like Cera’s perfect foil; Crystal Fairy is one of those films in which not much “happens,” in this case save for these two young characters’ competing yet oddly complementary attempts to seem worldly-wise. While obviously sensitive to their yearning for experience and for connection, Silva doesn’t overstate anything. (Detractors may decide that he understates everything.) The movie casts its spell subtly — even the much-anticipated trip mostly does away with drug-romp cliches, opting instead for easygoing restraint.