On New Year's Eve, six rich college friends -- Christian (Nick Stahl), Elizabeth (January Jones), Piper (Amber Benson), Adam (Eddie Kaye Thomas), Katie (Lori Heuring) and Benjamin (Derek Hamilton) -- gather together to play Taboo, a parlor game comprised of sexually explicit questions. Exactly one year later, the sextet reunites at a European castle where they find a package awaiting them. Inside are cards bearing a label related to their answers from the previous year: Prostitute, Infidel, Homosexual, Rapist, Hypocrite. And as each friend dies, one by one, it soon becomes clear that somebody in their group is also a murderer.