Brick, a low-budget debut feature by writer-director Rian Johnson, won a special jury prize at last year’s Sundance film festival for “originality of vision,” though that may say less about his movie than about what passes for originality in the movie business these days. Planned for seven years, shot in 20 days, and edited by the filmmaker on his home computer, the movie meticulously re-creates Dashiell Hammett’s brand of noir at a modern SoCal high school, with Joseph Gordon-Levitt as a teenage gumshoe trying to unravel the mysterious disappearance of his ex-girlfriend. Neither the choice of source material nor the idea of transplanting classic literature to a high school setting is particularly innovative, yet there’s no denying that Brick is weirdly expressive, often when it seems most artificial. What begins as the most gimmicky sort of genre retread somehow evolves into that most elusive of films: a personal statement.

Like most small movies, Brick opened in New York before arriving here, and early reviews suggest that neither its fans nor its detractors are inclined to take it too seriously. Stephen Holden, writing in the New York Times, panned the movie as a “flashy cinematic stunt” and compared it unfavorably to Alan Parker’s 1976 kiddie-gangster musical Bugsy Malone. In the New Yorker David Denby called it one of the year’s most entertaining movies but seemed to share Holden’s view of it as a game of dress up (“Part of the enjoyment is our knowledge that Brick was concocted by Hollywood kids on a serious lark, making use of a glorious strand of their inheritance”). Neither writer was willing to set aside his condescension long enough to consider that Brick might strike a chord with teenagers that he can no longer hear. High school may not be a shadowy world of moral anarchy and ruthless power relationships, of clueless authorities and back-alley punishments, but it can sure feel that way when you’re there.

This emotional authenticity might be easy to overlook because Johnson seems obsessed with replicating Hammett’s every stylistic stroke. The dialogue in Brick is so hard-boiled the water seems to have steamed away, leaving the egg rolling around in the pot. “Ask any dope rat where their junk sprang and they’ll say they scraped it off the Pin,” says one character. Cops are “bulls,” guns are “gats,” and a regular guy is a “yeg.” (Focus Features, the movie’s distributor, even cooked up a little promo booklet with a glossary of the slang.) Johnson rehearsed his actors for three months, urging them to read Hammett’s novels, and they deliver this studied argot with unflappable conviction. Lines that might have come off as ludicrous seem no more (or less) alien than the slang generated by teenagers as they try to construct an adult world distinct from the one their parents dangle in front of them.

Johnson shot the movie at his alma mater, San Clemente High School—what better locale for characters trapped by their environment than the place where you were trapped for four years? In visual terms it’s almost the reverse of Hammett’s landscape: his malignant cities were vertical and claustrophobic, whereas the school is horizontal and wide-open. But the sense of loneliness is just as acute—the school seems almost completely depopulated, as if classes had already let out. This surreal quality is heightened by locations such as a stretch of highway where a lonely (and utterly anomalous) phone booth stands at the side of the road and a black hole of a drainage tunnel that comes to represent the darkness at the center of the story. They’re all real places Johnson knew as a kid, and their seediness contributes to the sense of moral decay.

Neither the leathery dialogue nor the run-down settings would matter if Johnson hadn’t so perfectly transposed Hammett’s heartless criminal underworld to the shark-infested waters of high school, where the shifting tides of popularity can turn a friend into an enemy overnight. Brendan (Gordon-Levitt), the steely hero of Brick, is a sort of teenage Sam Spade, a loner who looks out for number one and survives by avoiding entanglements. But Emily (Emilie de Ravin), his ex-girlfriend, lacks Brendan’s sangfroid and has begun to climb the social ladder by attaching herself to a haughty cheerleader (Nora Zehetner). After a panicked phone call to Brendan, Emily vanishes without a trace, and before long he begins to suspect that she’s gotten in over her head with the muscle-bound Tugger (Noah Fleiss) and his secret employer, a heroin dealer known only as the Pin (Lukas Haas).

Besides Brendan, Tugger and the Pin are the most interesting characters in Brick; Johnson has studied Hammett’s fiction well enough to understand that the most fearsome men can also be the most vulnerable. Tugger is introduced as the human equivalent of a Sherman tank: clad in the hip-hop uniform of knit hat and wifebeater, he appears in the background and marches directly into the frame to punch Brendan’s lights out. During a subsequent encounter in a mall parking lot, Tugger drives straight at Brendan, veering away only at the last moment. Yet by the end of the movie this awesome meathead has become a poignant figure, wounded by love and conscious that—like Wilmer in The Maltese Falcon—he’s nothing but a pawn to his boss.

Tugger is stupid but strong, the Pin smart but frail. Afflicted with a clubfoot, he’s usually seated and walks only with the help of a silver-tipped cane. He’s the most baroque figure in the movie, and Johnson can’t resist playing him for laughs: the Pin runs his heroin empire from a paneled basement room in his parents’ suburban home, and in the movie’s most absurd scene he, Brendan, and Tugger negotiate tensely, then head upstairs for cookies and milk served by the Pin’s cheerfully oblivious mother. Like many of Hammett’s criminal masterminds—Paul Madvig in The Glass Key, Kaspar Gutman in The Maltese Falcon—the Pin is isolated by his power, and he seems to admire Brendan for his shrewdness and self-possession. In a world as mistrustful as theirs, mutual respect is the next best thing to friendship.

Hammett once described Sam Spade as not a real detective but the man every real detective aspired to be, and Brendan is much the same—not a real teenager by any stretch of the imagination but a walking catalog of all the traits teens covet. He’s cool under pressure, acts quickly but wisely, and holds people at arm’s length, the better to evaluate their hidden motives. “Who are you, sitting back here, hating everyone?” Emily asks him in one flashback sequence.

Johnson was lucky to land Gordon-Levitt for the role; a veteran of the sitcom 3rd Rock From the Sun, he’s proved a formidable dramatic actor in indies like Manic (2001) and Mysterious Skin (2004), and in Brick he holds the screen as powerfully as Jack Nicholson in Chinatown. Johnson has cited that classic noir as another of his models, and in Brick there’s a similar sense that the truth will always be ugly. By the end of the movie Brendan has learned more about himself than he might like to know, but living with one’s mistakes is a constant of the genre, not to mention adulthood.