Present Day: Brendan sits by a tunnel, staring at a dead girl (Emily) lying in the water.
Flashback (2 days previous): Emily slips a note in Brendans locker telling him to go to a specific phone booth. She calls the phone booth, and they talk for a little. She says shes in trouble, but uses words Brendan doesnt know to describe the problem (Poor Frisco, Pin, brick, Tug). A black car drives by and Emily screams. The passenger in the car drops a cigarette with a blue arrow on it.
Brendans friend, Brain, tells Brendan that Emily has been trying to hang out with the popular group of kids (the upper crust). Brendan breaks into Emily locker and takes a ripped red piece of paper out of her notebook. He talks to his ex-girlfriend, Kara, and finds the complete piece of red paper: an invitation to a party. The invitation has a number on the back, Brendan calls it, and talks to Laura. Once he says he has Ems invite, she tells him where and when the party is. At the party, Laura and Brendan talk upstairs. She tells him that Emily has been hanging out with someone behind a café in town, called Coffee and Pie, Oh My. He follows Laura outside when she leaves and sees her talking to Tug by his car.
Brendan goes to the café, and we meet Dode. Dode has been dating Em. When Dode leaves, Brendan follows him and sees him give Em a slip of paper.
Brendan and Emily meet up. She says the only way for him to help is so get over her. As they hug, he takes a notebook out of her pocket. Inside is the note Dode gave her. There is a symbol on the paper, which Brendan does not understand. He goes to his friend Brain to ask him what it means. Brain says that the symbol refers to a meeting place in town, but he doesnt know which one.
Late that night, after the time Em is supposed to be at the meeting place, he realizes that the symbol stands for the tunnel. He goes to the tunnel, and the flashback catches up to present day. Emily is dead, and Brendan wants to find out what happened.
Voiceover turns into a flashback: Brendan and Emily fighting, she slaps him and he pushes her. They keep referencing somebody named Jerr. Jerr and Brendan used to have a small drug dealing partnership, but Brendan ratted him out to the vice-principal. It is implied that Jerr and Em had some sort of relationship, and that is why Brendan ratted on him.
Present day: Brendan goes to the Brain to find out what the words Emily said on the phone meant. Brain doesnt recognize many of them, but he knows that the Pin is a big-time drug dealer in town, and that he is linked to the popular kids Em was trying to be friends with. Brendan picks a fight with one of the popular kids, Brad, in the parking lot, to grab the Pins attention. Laura tries to talk to Brendan, but Brendan says he cant trust her. Tug then comes up and punches him. Brendan is called into the Vice-Principals office, and they make a deal. The VP will stay of Brendans back if Brendan tells the VP whats going on, otherwise, Brendan will be blamed.
Brendan walks through a parking lot and sees the black car from the beginning. He holds a brick over the car, which makes Tug come outside and punch Brendan. Brendan puts up enough of a fight that Tug brings him to the Pin. Brendan is able to see out of the trunk and sees the Pins address. Brendan meets with the Pin, and the Pin says he will pay Brendan to not rat him out, but first he wants to check Brendans story. Either the Pin will hire him or hurt him.
Laura tells Brendan that Emily stole a brick (brick=heroin), because she was so addicted she wasnt herself.
At school, a guy comes up to Brendan with a knife, and we assume he is associated with the Pin. After Brendan knocks him out, the Pin pulls up in a van, and tells Brendan he has decided to pay him.
Dode calls Brendan, and tells him that he saw Brendan with the body, and threatens to tell somebody.
Brendan goes to talk to Brain. Brain shows him a newspaper, which says that Em has been reported missing. He also tells Brendan that Frisco (poor Frisco, one of the things Em said to Brendan on the phone) took a dose of heroin and is in a coma, because there were traces of laundry detergent in it.
Brendan sneaks into the Pins house, and finds a brick in the basement. Tug comes in and punches him. Brendan gets Tug to side with him by saying he gets angry when the Pin isnt honest, Tug feels like Brendan understands him. Tug tells Brendan that there were 10 bricks. They sold 8, and the 9th one disappeared, then came back, and that was the brick that killed Frisco. They still have the 10th brick. Tug pretends he doesnt know Em, but the Pin tells Brendan that they dated.
Dode arranges a meeting with the Pin, he says he knows who killed Emily. On the way to their meeting, Brendan gets sick from swallowing too much blood. He confronts Dode and Dode tells him that he thinks Brendan killed Emily. Dode reveals that Emily was pregnant with Dodes baby. Tug, the Pin, Dode, and Brendan meet at the tunnel. When Dode says he knows who killed Emily, Tug shoots him and kills him.
Brendan is brought to Tugs house. Tug confesses to killing Em. Tug says there is a war between him and the Pin, and that Brendan is on his side. Brendan organizes a meeting between Tug and the Pin, to try to sort things out. Laura comes in to comfort Brendan, and they have sex. We see her cigarette, and it has a blue arrow on it, just like the one from the beginning.
Brendan calls Brain and tells him to call the police at 4:15, and to say that there are drugs in the back of Tugs car. At the meeting between the Pin and Tug, the Pin wants to make sure that the last brick of heroin has not been messed with, so he asks Tug to take a dose off of it. When Tug refuses, because the police will be called soon, Brendan agrees to take the dose. When someone goes upstairs to get the brick, it is gone. A shot is fired upstairs. Tug and the Pin fight, Brendan takes Tugs gun, as Brendan is leaving, we hear the Pin calling for his help. Brendan tosses the gun back into the room and escapes in time. We see that Emily is in Tugs trunk, and the police will find her.
The next morning at school, Brendan meets with Laura. Brendan lies to Laura and says he never made it to the Pins, so Laura tells Brendan what happened. 6 were found dead, including the Pin, Tug, and Emily. Brendan then tells her and the viewers what Lauras role in all of this is. Laura was the one who stole the 9th brick, and she took half and then cut the rest. After Frisco was put in a coma from using some of it, Laura needed someone to blame, and she had Emily. The Pin sends Tug to go talk to Em and find out what happened, and Laura tells Em to tell Tug that shes pregnant with his baby. Anyone who knows Tug knows what he would do, so Laura knew that he would kill Em. Laura had taken the 10th brick, so that a huge fight would break out at the Pins. Brendan tells her that he slipped a note to the Vice-Principal telling him to search her locker, where we see the VP finding the brick. Laura then tells Brendan that Emilys baby was his, and she was going to abort it.