Elizabeth Halsey (Cameron Diaz) is a lying, foulmouthed, ruthless, and inappropriate teacher. She drinks, gets high, and can't wait to marry a meal ticket to get out of her bogus day job. When she's dumped by her rich fiance, she sets her sights on a rich, handsome substitute (Justin Timberlake) while shrugging off the advances of the school gym teacher (Jason Segel).