For about half its running time, Brick is tantalizing, transporting moviemaking — writer/director Rian Johnson taking generic hard-boiled drama and dialogue and transposing them from old-school crime dramas to a high-school milieu. Joseph Gordon-Levitt is pretty terrific as Brendan Frye, the shy type of high-schooler who eats lunch in isolation, rather than inside the cafeteria. He turns gumshoe after a phone call from his ex-girlfriend reveals her to be in a big heap of trouble; before long she’s face down in a drainage ditch and Rian is running down the cryptic clues that put him on the trail of her killer.

Brendan solicits advice from nerdy confidante The Brain (Matt O’Leary), butting conversational heads with a macho jock (Brian J. White), a half-pint femme fatale (Nora Zehetner), and a crime lord (Lukas Haas) working out of his mom’s basement. Of course, he gets the crap kicked out of him and, of course, he gets right back up afterward. There’s a great tete-a-tete with his assistant principal (Richard Roundtree), the closest thing to a lawman here, that really defines the game Brick is playing with its displacement of crime-film clichés. (“You got a discipline issue with me?” he barks. “Write me up or suspend me.”) And there’s Brendan himself, Gordon-Levitt working his every scene with a sad-sack expression that reads as both condescending smugness and soul-crushed dejection.

Now, folks keep describing Brick as film noir, but I can’t see that this movie has much noir in it. Certainly the visual strategy is anything but noirish, opting for lots of wide-open exteriors and well-lit interiors with nary a chiaroscuro set-up in sight. (The most striking visual is aggressively anti-noir in its literalism, a shot from a nightmare sequence that has a rivulet of water suddenly take on the shiny, crackling blackness of a body bag.) The dialogue is obviously inspired by old-school crime novels, but the cinematic antecedents are much more Blue Velvet and Miller’s Crossing than The Maltese Falcon and The Big Sleep. There’s none of the discomfort of tight spaces — the settings are more evocative of a teenager’s awkwardness in exploring the farther corners of their world, or his discomfort in facing the wide-open future that yawns tauntingly before him.

Accordingly, this must be one of the only high-school films ever made that doesn’t even pretend to be interested in anything that happens in the classroom. (Johnson apparently shot on location at his own school, but the only scenes that contain real visual references to the setting take place in front of a row of lockers or on a football field.) But this stuff does evoke the real feelings of those high-school years, when teenaged personal politics felt bigger than life and every emotion was amplified to the level of heartbreak. As long as Johnson seems to acknowledge how absurd all of this is, Brick earns its pervasive sense of self-satisfaction.

But there’s a point where the proceedings turn more serious, which bummed me out. Johnson seems to start mistaking his derivative talespinning — Brick is essentially a Dashiell Hammett parody — for gripping, credible drama in its own right. That’s a mistake, because once you get past the well-drawn set pieces and credibly hard-boiled dialogue springing from the mouths of attractive young people instead of more grizzled oldsters, Brick devolves into little more than the latest reflexive crime drama inspired by the work of Tarantino and the Coen Brothers.

The emotional payload depends on audience identification with Brendan, whose investigation works as a sort of battering ram against his own innocence, revealing things about Emily that he probably never wanted to know. Johnson doesn’t have the constitution to take the story into Laura Palmer territory, and I think he miscalculates by relying too much on clichés, which make it hard to float red herrings or place the allegiance of different characters in question — if you have a nodding acquaintance with Hammett, the denouement comes as no surprise at all — and emphasize the occasionally misguided artifice of the whole enterprise. Still, it’s a willful little film full of stand-out set-pieces that are executed with the kind of aplomb that’s exciting coming from a first-time writer/director. Johnson’s follow-up will have to prove that he has something on his mind besides all that cleverness.