The main character of the movie is the dead sister, the entire thing is orbiting around her absence, it's also why the POV keeps jumping from character to character, because it's following a ghost
@KentuckyConjurer Hmm she could just be a giant red herring they introduce some really awkward weird person so we obviously believe she is the killer but it is really someone we will never think of #TheLastDriveIn#MutantFam#GraduationDay