Seventeen-year-old Millie Kessler is just trying to survive high school when she becomes the newest target of the Butcher, her town's infamous serial killer. The Butcher's mystical ancient dagger causes him and Millie to wake up in each other's bodies, and Millie learns that she has just 24 hours to get her body back before it is permanent. While Millie races against the clock to reverse the curse, the Butcher discovers that having a female body is the perfect cover for a little killing spree.