When we meet Brendan (Joseph Gordon-Levitt), he has lost his ex-girlfriend Emily (Emilie De Ravin) for the second time. As the audience of Brick, we don’t know that yet, but her lifeless body facedown at the mouth of a runoff tunnel is once enough. Crouching feet from her, Brendan doesn’t appear mournful or even surprised by her death, a hint that he really lost her long before then. Instead he looks to be formulating a plan. That it’s to find her killer is not unexpected. That Brendan is still in high school, is.

In the film Brick, the audience is thrust into an alternate reality, one where a high school student finds himself more capable of solving murder than the authorities. Brendan hides Emily’s body in the tunnel to give him time to track down the killer before the police get involved and screw everything up. In this reality, high school students are just as self-involved and unhelpful as in ours, and no one at school wants to answer Brendan’s questions about the goings-on of his ex-girlfriend. He’s just the jilted ex-boyfriend. But there is more to it than that. We learn Brendan’s done his own snooping before having six months ago turned over to the school administration a student named Jerr who was using Emily. We never learn the details, but it is enough to know that Brendan is swimming against the current, which is the most difficult way to get through high school let alone solve a murder. It doesn’t take long to learn that Emily her troubles hadn’t ended with Jerr and that what she was involved in is a favorite reason behind guest assembly speakers and random locker searches.

Brendan is played with such confidence by Gordan-Levitt that it’s just as easy to accept a world where a student with such moral conviction could exist. Whether it’s taking on the drama club’s queen or the school’s tweakers, Brendan comes in with zero braggadocio and absolute righteousness. He doesn’t lie or manipulate to get his answers, but he’ll get his answers with words or fists. Brendan is not a hero—no one gets saved—but he is the one person who you’re never unsure is right among all the wrong.

Brick leans heavily on the conventions and clichés of film noir but it acknowledges its influences head-on. Brendan doesn’t wear a tan trench coat but he does wear a tan jacket that he often digs his hands into when he’s not using them to give a beating to a dope peddler or football player. His moral compass is fixed. His obstinance is firm against the femme fatale, the drug dealing henchman, or the hardass Assistant V.P. who only lets Brendan run his own agendas because they happen to also benefit the school’s. The tropes are there but they are not out of place among angsty adolescents dealing with much the same problems the nearly invisible adult population believes are all their own.

Director Rian Johnson has said that some of the biggest influences for Brick were the novels of Dashiell Hammett and that he specifically imitated Hammett’s style when developing the language and tone of the movie. Johnson has also said that the heightened dialogue was a way of elevating the production’s quality without having to put the film’s limited budget into expensive sets, costumes, etc. The use of language is so esoteric that the few indie theaters that screened Brick in 2006 provided pamphlets called “Brick Talk,” a glossary of terms used in the film. Despite its influences, the dialogue of Brick feels wholly its own. Language drives the world of Brick and everything about Brendan’s unrelenting intentions can be found in what he tells his only ally when he decides to go after Emily’s killer: “No, bulls would gum it. They’d flash their dusty standards at the wide-eyes and probably find some yeg to pin, probably even the right one. But they’d trample the real tracks and scare the real players back into their holes, and if we’re doing this I want the whole story. No cops, not for a bit.”

Brendan finds the whole story. He does it with smarts and fists. But like all great detective stories, the truth doesn’t make anything better. It just reaffirms what the detective already knew.