EVERY SENSITIVE high school student is a detective, finding a way through the world with only a handful of unreliable clues. They suss out the mysteries of their lives. They live in a half-world—half petulantly childish, half brutally adult. They are subject to betrayal at a time when beautiful young women (or beautiful young men) are at their most dangerous. They are blind-sided by the sudden change of mood that can bring a seemingly beautiful friendship to an end. And punks, thugs and squealers lurk everywhere.

Still, trench-coated detectives are out of fashion today. In today's schoolyards, the lore of superheroes supplies the favorite code for how an adolescent keeps things masked and anonymous. But I love Rian Johnson's Brick, just love it, for the way it recalls what it was like to read a Philip Marlowe novel in high school.

The film's first image shows us mud-spattered, bare female legs. Brendan (Joseph Gordon-Levitt) has just discovered the corpse of his ex-girlfriend lying in a mossy wash. In flashback, he recalls the previous few hours: a message dumped in his locker, a choked-off call caught at a telephone booth and a cigarette butt bearing a certain insignia.

Our hero, an army-jacketed, battle-scarred vet of a particularly warlike "tough but fair" English class, spends the movie trying to find out who did it. With the help of an equally solitary library rat called "The Brain" (Matt O'Leary, a face you never quite see), Brendan goes on a manhunt among the cliques of his Orange County high school. The pressure builds as the school's head cop, the assistant vice principal (Richard Roundtree), imposes the usual 72-hour deadline.

Just as Marlowe had to shake down the blue bloods and wharf rats alike, Brendan must trace a dangerous path through the school's cliques: the painted teen Dietrichs of the drama club; the moneyed "soches" gathered at an ominous "Halloween in January" party; the muscle boys of the football team; and the lurking stoners behind the coffee shop.

Most dangerous is Brick's answer to bruiser Moose Malloy (Noah Fleiss as "Tugger"). After getting beaten up a lot, Brendan plunges into the underworld run from a knotty-pine basement by a clubfooted kingpin. He is called Pin for short and played by Lukas Haas with a homemade haircut: "He's supposed to be old, like, 26." Pin is responsible for the story's MacGuffin—a brick of some lethal contraband powder cut with laundry detergent.

Johnson hasn't copied the visual style of Warner Bros. in the 1940s—which is a good thing, because who needs another Bugsy Malone? Instead, the film mixes the pleasures of detective watching with the visual ethereality of a Gus Van Sant thumbsucker. Since there aren't any dark alleys to speak of, Johnson stages the adventure in the open spaces of his native San Clemente, shooting against retaining walls and the flooded, off-season football field closed off by the elevated I-5 highway. Brendan has a lethal rendezvous in a parking lot chilled by a glassine keyboard soundtrack by Nathan Johnson.

Brick works both the ironical wisecrack of the Bogart days and the due note of pathos. (The Pin could have been somebody. He's sensitive; he reads Tolkien.) Gordon-Levitt—the most interesting actor under 25 today on the basis of this and Mysterious Skin—brings a natural wit and grace to the role of shamus, in both the quips and the fight scenes. Being slighter than the jocks, Brendan knows the wisdom of running for his life and the reliability of a flatfooted kick to the shins.

Fleiss, Haas and an actress named Meagan Good are as triumphantly like a John Huston stock company as anyone could want. Good plays Kara, the school's prima donna theater department actress, always posed in front of her makeup mirror.

Greeting her, Brendan asks, "Still picking your teeth with freshmen?" "You were a freshman once ... ," she murmurs. The good/bad female lead is called Laura—you don't have to be Halliwell to get that reference—and Nora Zehetner makes her the coolest and most untrustworthy femme in recent fataling. A danger sign: She wears hats. (A newspaper reporter I knew once advised me, "Girls who wear hats are trouble.")

The conceit of a high-school detective film sounds slight, but Brick is not just a lark. It is surprising how seriously you can take this adventure. Like a great detective novel, it makes you re-examine mysteries in your life that you never were quite able to solve. On a different level, the jargon-loaded dialogue is enough to make anyone who loves words warble like a canary.

Brick offers an original, invigorating blend. It is not quite film noir or film pastel, or Twin Peaks knockoff or clever-clever parody, but wise, sure entertainment with blood on its knuckles. Like the much-lamented Buffy the Vampire Slayer, this movie takes the seemingly life-and-death sorrows of high school and literally makes them a matter of life and death.

Brick (R; 100 min.), written and directed by Rian Johnson, photographed by Steve Vedlin and starring Joseph Gordon-Levitt, Nora Zehetner and Noah Fleiss, opens Friday valleywide.

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