When a disturbed high school student, dressed in a prom suit and clown mask, named Ray Lester, kills all the friends of his ex-girlfriend and classmate named Ellie Olamberria, whom he loves, in a mad attempt to force her into a return relationship with him, the boy is captured and sent to prison. However, a year later, at her high school prom, Ellie is about to come face to face with the killer once again. Will Ellie and her friends escape the psychopath?
