High school student Brendan Frye (Joseph Gordon-Levitt) discovers a note directing him to a pay phone, where he receives a call from his terrified ex-girlfriend Emily Kostich (Emilie de Ravin), begging for help. She mentions a "brick", "Tug", and "the Pin" before abruptly hanging up, apparently afraid of a passing black Ford Mustang, from which a distinctively-branded cigarette is thrown.
Unable to locate Emily, Brendan enlists his friend Brain (Matt O'Leary) for help. An encounter with another ex-girlfriend, Kara (Meagan Good), leads him to a party held by flirtatious upper-class girl Laura Dannon (Nora Zehetner) and her boyfriend, Brad Bramish (Brian J. White). Laura points Brendan to Dode (Noah Segan), who arranges a meeting with Emily.
Emily dismisses the phone call and tells Brendan to let her go. Brendan steals her notepad and finds a note that leads him to her dead body in a tunnel the following morning. Distraught, Brendan decides to investigate her murder, hiding the body to avoid police intrusion. Brendan discovers that "the Pin" (Lukas Haas) is a secretive local drug baron. As Brad is a frequent drug user, Brendan picks a fight with him, hoping to attract the Pin's attention. Later, a man wearing a beanie attacks Brendan.
Brendan sees the black Mustang in a parking lot and tries to break into it. He is beaten up by the car's beanie-wearing owner. Rather than fight back, Brendan repeatedly asks to meet the Pin. The man is Tug (Noah Fleiss), the Pin's main enforcer, who reluctantly takes Brendan to the Pin's house.
Brendan asks the Pin for a job, and the Pin says he will investigate him and either hire or kill him by the next day. Laura reveals herself and drives Brendan back to school. She explains that Emily stole a "brick" of heroin after being rejected by the Pin's operation. Laura offers to help Brendan, but he distrusts her.
