 Julian and his few friends that actually managed to escape Necropolis have all enrolled in college and are trying to put their experiences with Hybratech behind them forever. Soon after, Jenny and Julian find a strange chemical container in a hidden room. In an effort to find out what this chemical, labeled as Trioxyin-5 is, they take it to their friend Cody for screening. However, Cody soon finds a way to make party drugs from it and try to earn some quick cash. Cody then makes a huge quantity of a drug called  Z  that he begins to sell to the college kids. Soon, Halloween approaches, and almost all of the college kids have already taken  Z . After the drug takes effect and turns the kids into zombies, the Halloween costumes everyone is wearing make it hard to distinguish the living from the undead.