Elizabeth Halsey, portrayed by Cameron Diaz, is a disheveled teacher in the Chicago area who navigates life with a reckless attitude, indulging in heavy drinking, swearing at her students, and using drugs. After a short-lived engagement to a wealthy fiancé convinces her to leave her teaching position, Elizabeth finds herself back at school when he abruptly ends their relationship, exposing her true intentions as a gold digger.
Determined to win over the charming substitute teacher Scott Delacorte, portrayed by Justin Timberlake, who also comes from money, Elizabeth faces competition from their colleague, Amy Squirrell, played by Lucy Punch. Meanwhile, the school's gym teacher, Russell Gettis, takes an interest in Elizabeth, complicating her life further. Desperate to impress Scott, Elizabeth dreams of breast augmentation but lacks the funds to make it a reality.
As Elizabeth tries to navigate the growing tension with Amy and her feelings for Scott, she resorts to dubious methods to raise money for her surgery, which include a class car wash and persuasive tactics on parents for “special care” of their children. However, her plans quickly unravel when Amy spreads rumors about Elizabeth’s intentions and tries to paint her in a bad light.
In an ambitious turn of events, Elizabeth decides to dramatically improve her teaching methods in hopes of achieving a bonus for the top-scoring class in state exams. But the pressure compounds as Scott begins displaying interest in Amy. Undeterred, Elizabeth forges ahead with a plan that takes a darker turn. She adopts a deceptive persona as a journalist to steal the state exam, using both seduction and manipulation to get what she wants, even capturing compromising photos of the official in the process.
The stakes escalate when a field trip presents an opportunity for Elizabeth to eliminate her competition; she sabotages Amy by laying a trap that keeps her from attending, allowing Elizabeth to spend time with Scott and ultimately leading to a steamy encounter. However, her careless actions prompt a series of events that threaten to expose her misdeeds.
As the plot thickens, Elizabeth faces the repercussions of her choices. When her schemes start falling apart, she finds herself blackmailing to cover her tracks. Despite her intentions, Elizabeth learns about the consequences of superficiality and deception, eventually realizing that her feelings for Scott were shallow.
By the end of the school year, a transformation in Elizabeth becomes apparent. Opting against the breast surgery, she embraces her authentic self and builds a genuine relationship with Russell, moving on to become the school's new Guidance Counselor, leaving her troubled past behind. This journey of self-discovery underscores the reality that sometimes, the superficial desires we chase can lead us to the most profound revelations about ourselves.
