Shannon, always the center of attention, invites a bunch of her friends to a 'Mardi-Gras' theme party at her house. As the party winds down, she overhears three of her friends talking while playing pool. Justin is telling Paul and Eric of his plans to ask his girlfriend (Heather) to marry him. This news makes Shannon jealous.After everybody but Justin leaves, Shannon attempts to seduce him- unsuccessfully. Not to be deterred, she tries to convince Justin that his girlfriend has been cheating on him... with his best friend (Ryan)! Justin tries to call Heather (who is at home with the flu) to refute Shannon's claim, but only gets voicemail. Meanwhile, Justin seems to be getting a little woozy and then blacks out.Waking-up the next morning naked in bed, Justin tries to remember what happened while Shannon picks up where she left off from the night before- and claims they had sex! Solving one clue at a time, Justin slowly pieces together that Shannon has been deceiving him. As he discovers a bottle of Valium and starts remembering things from the night before, he realizes that Shannon had drugged him. With everything exposed as a string of deceptions, Justin now doubts that there was any sex. Shannon lays down one last threat about having evidence and showing it to Heather. Justin storms out of his former friend's house, but Shannon has a little suprise for later- a tape of her and a 'willing' Justin!