Joel, a caustic 1980s film critic for a national horror magazine, finds himself unwittingly trapped in a self-help group for serial killers. With no other choice, Joel attempts to blend in or risk becoming the next victim.
A cult kidnaps a young girl and sacrifices themselves by the locust moon. The girl awakes, surrounded by corpses. Years later, the locust moon rises again and the girl is captured by a surviving cult member, informing her demon is growing inside all these years.
It follows a college student as she boards a party train for Halloween, and ends up fighting for her life when a mysterious assailant begins killing the people one-by-one.