Bickering step-siblings together quietly control much of the social lives of the students in an affluent NY prep school. Sebastian sees himself as a kind of Don Juan, who always gets his woman, while Katherine would rather enact revenge on ex-flames and corrupt incoming freshmen. One day, Kathryn and Sebastian, driven by a mutual lust for each other and a love of messing with innocent young people's lives, hatch a nefarious plan, and place a kind of bet. Sebastian is to woo and bed the daughter of the new headmaster (a very adamant virgin with plans to only "wait until marriage"), and if he is able to accomplish this seemingly impossible task, he can have his way with Kathryn - the one woman whom he KNOWS he can not have. If he is unable to seduce the ice queen, however, Katherine gets his classic car.