Six school friends meet up for a drug-fuelled Fourth of July weekend on a remote island. What they don't know is the drug they scored is not what it seems; it's actually a new bioactive compound peddled by a sadistic right-wing terrorist organisation. Anyone consuming it is then exposed to a virus causing fits of psychotic rage, mind-bending chaos and cannibalistic murder. Only one refused to partake and now she must fight to survive as everyone around her, including her fiancé, tries to savagely kill her.