Brendan Frye (Joseph Gordon-Levitt) is a loner at his high school, someone who knows all the angles but has chosen to stay on the outside. Until the day that his ex-girlfriend, Emily (Emilie de Ravin), reaches out to him unexpectedly and then vanishes. Brendan's feelings for her still run deep; so much so, that he becomes consumed with finding his troubled inamorata.
To find her, Brendan enlists the aid of his only true peer, The Brain (Matt O'Leary), while keeping the assistant vice principal (Richard Roundtree) only occasionally informed of what quickly becomes a dangerous investigation. Brendan's single-minded unearthing of students' secrets thrusts him headlong into the colliding social orbits of rich-girl sophisticate Laura, intimidating Tugger, substance-abusing Dode, seductive Kara, jock Brad and—most ominously—non-student The Pin (Lukas Haas). It is only by gaining acceptance into The Pin's closely guarded inner circle of crime and punishment that Brendan will be able to uncover hard truths about himself, Emily, and the suspects that he is getting closer to.