After a day of teenage shenanigans, high school best friends Lucy, Kat, and Peter find themselves breaking into an abandoned house for fun. Inside, Peter discovers an ancient book with the words "Quomodo si vocare daemones" (Translation: How to Summon Demons) on the front. Days later, during gym class, Lucy begins to suspect that Peter is in fact possessed by a demon. In a search for answers, Lucy and Kat venture back to the abandoned house in hopes of finding the book and reversing whatever effects it has had on their friend. Along the way, the duo must try to survive encounters with segway riding school bullies, Demon Peter himself, and a local drug lord.