Cassie Keller (Emily Osment) is a Goth subculture girl and a prankster who just moved with her family to a new neighborhood and school. She loves to play scary pranks on the popular kids at school and her younger brother Max (Alex Winzenread). Priscilla Wright (Brittany Curran), a school bully, is elected Halloween Queen for the school's annual Halloween fair. Cassie retaliates against rude comments Priscilla made to her by putting live cockroaches in the Halloween piñata, which Priscilla is due to break; she beats the piñata and is showered with the insects after it breaks, and is mocked by the student body at the party and in the following days at school.