Sixteen-year-old Kristina Snow embarks on a court ordered visit with her father, whom she hasn’t seen or heard from in eight years. When she arrives in Albuquerque N.M., she finds that he isn’t quite the man she’d imagined. He smells of smoke and works in a bowling alley. Left alone for most of her visit, Kristina meets Adam, a young man who lives in the same apartment complex. Attracted to him, she pretends to be Bree, the person she is in her daydreams. Bree is confident, brazen and flirtatious.
A week of clandestine talks and kissing lead to the night when Adam asks Kristina to get high with him. She agrees, but doesn’t like the mellow feeling marijuana gives her. She wants to try the drug her father takes that makes him high for days.
Adam gives Kristina her first hit of methamphetamine, or “the monster” as she calls it, in a back room of the bowling alley where her father works. From that experience, she is hooked on the intense rush the drug gives her. She and Adam get high several more times before Kristina heads home to Reno, Nev.
Initially, Kristina struggles to fit back in with her family. When she calls to talk to Adam, she learns he is visiting an old girlfriend in the hospital. She wonders how sincere his feelings were for her, especially when he tells her that they should be allowed to date other people.
Kristina attends her stepfather’s company picnic at a water park. While there, she again pretends to be Bree and flirts with two boys. One is Brendan, a handsome lifeguard. The other is Chase, a boy from school with a bad reputation. Kristina revels in the boys’ attention until her mother notices a tattoo that Adam inked on her thigh. Her mother orders her Grounded Until Further Notice or GUFN.
She spends the rest of her summer doing extra chores and watching television, which gives her more time to plot ways to party with the monster. Her chance comes two days before the beginning of school. Although still grounded, Kristina calls Brendan to help her sneak out of the house. He takes her to a well-known party spot, and the two drink beer and get high.
Still riding the effects of meth, Kristina barely makes it through the first day of school. She gets into an argument with her mother, which causes Kristina to vow to try harder to break her growing addiction. Her resolve remains for a week. Then Brendan asks her for another date. She raids her savings and asks him to buy her some meth before he picks her up. Instead of partying with a crowd, Brendan drives her to a secluded grove of evergreens. After they enjoy a hit of meth and a six-pack of beer, he rapes Kristina.
Kristina turns to Chase for emotional healing. Chase is patient and comforting and the two begin dating. But Kristina’s life continues to spiral downward as she delves ever deeper into the drug culture by becoming a dealer. The only thing that keeps her from destroying herself entirely is discovering she’s pregnant. She is horrified to learn that the father is Brendan, not Chase.
Even with this news, Chase asks her to marry him. She refuses, knowing she’s not ready for the commitment. She pressures Brendan into giving her money for an abortion, but while waiting at the clinic, she feels the baby move and can’t go through with the procedure. She tells her parents and accepts their help in raising her child. Even as she embarks on motherhood, Kristina admits to still heeding the siren call of the monster.