Chuck (Chris Weitz) is now a Los Angeles music-industry executive with a beautiful fiancée (Beth Colt) and a finely honed attitude of hip capitalist moxie. He wants nothing to do with this pathetic case of arrested development who still dresses like a nerdy sixth grader, sucks on Blow Pops as if they were sugary sexual pacifiers, and dotes on cut and paste photo collages of his youth. Buck, who likes to play his favorite kiddie record (the insidiously infectious chorus goes, ''Oodley-oodley oodley-oodley oodley-oodley fun fun fun!''), speaks in the lazy, singsong cadences of prepubescence, when kids haven't yet learned the art of calculating how to present themselves. He's an overgrown goofy child, but he's consumed by a single passion. To Buck, his friendship with Chuck is more than just a memory: It's life itself -- it's the paradise from which he'll fall and crash if he ever allows himself to grow up.
Mike White, the star of ''Chuck & Buck,'' also wrote the script, and if he doesn't look like an actor, that's because up till now, at least, he hasn't been. (He has worked mainly as a writer and producer on ''Dawson's Creek'' and ''Freaks and Geeks.'') White has a genially boyish, squished-froggy face, with barely visible downy eyelashes and a skewed-toothed leer of a smile. He could be Jerry Seinfeld's runty cousin, yet there's a dazed and disquieting sensuality to his eyes. The trick of the movie is this: Buck may have the mind of a child (whenever he's rejected, he lapses into tears), but he has the hormones, and the instinctual predatory cunning, of an adult. When his mother dies, he packs up his toys and his record player and moves to L.A., where he begins to pester his old friend, visiting his office and calling him around the clock. He also scrawls out and stages a fairy-tale play, hilariously revealing in its sub-Ed Wood naïveté, about their lost garden of friendship. Buck may be living in denial of his adulthood, but Chuck, we sense, is in denial of something else. Adulthood is all that means anything to him.
In form, ''Chuck & Buck'' is an idiot-savant stalker comedy, not unlike, say, ''What About Bob?'' Yet if the result is often joltingly funny (attending a party at Chuck's, Buck, completely inept at small talk, says, ''I like your house. It's very... old person-y!''), it's also bristling with a kind of kinky suspense. Outlandish as it is, the movie is played absolutely straight, and that's its deadpan brilliance. The director, Miguel Arteta (''Star Maps''), shot ''Chuck & Buck'' on digital video, and though it's framed like a conventional feature, with none of the frazzled, handheld flamboyance of the Dogma 95 films, you feel the presence of the video camera in the virtuoso, documentary-like intimacy that Arteta achieves with his actors.
At times, the screw-loose peephole humanism of ''Chuck & Buck'' is reminiscent of Todd Solondz's ''Happiness,'' except that Arteta harbors no impulse toward caricature. His intimacy extends to everyone on screen, from Chuck the beleaguered yuppie hotshot to the scene-stealing Lupe Ontiveros as Beverly, the no-nonsense theater manager who helps Buck stage his play. As the movie goes on, we're lured into Buck's romantic, nearly Proustian dream of a boyhood friendship that's more freeing in its happy-time ''fun'' than anything the world of maturity allows. A viewer's reaction will ultimately pivot on the moment when Chuck, back in Buck's room, says, ''I remember everything,'' and then proceeds to relive it. For some, what follows may appear far-fetched, but I felt as if I were watching the past literally come to life. That's about as close to magic as contemporary movies get.