Millie Kessler is just trying to survive the bloodthirsty halls of her high school and the cruelty of the popular crowd, but her senior year becomes the least of her worries when she's targeted by her town's infamous serial killer. When The Butcher's mystical ancient dagger causes him and Millie to wake up in each others bodies, Millie must race against time to get her body back before she's stuck as a middle-aged maniac forever.