Alex Harris has it all: he's popular, he's class president, and the ladies can't get enough of him (in particular, fellow student council member Jenny Clark). There's just one problem... he's in love with his twin sister, Katie. Meanwhile, Katie has been feeling that something's missing from her relationship with her long-term boyfriend, Mark. With their senior prom looming, the two siblings must decide how to deal with these feelings which they can no longer deny. One thing's for certain - this year's prom promises to be a night to remember, even if some may want to forget.