For a year, the Earth has been plagued by a mysterious virus pandemic, which most of the world's population has become accustomed to and has taken lightly. Jim and Kat, a young couple, continue to live their lives as usual. However, one day, the virus mutates in an unexpected way, stripping infected individuals of their humanity and triggering uncontrollable outbursts of aggression and lust. Jim is caught in a crowded cafe by the new virus, while Kat is on the subway during rush hour. Now, the couple must work hard to reach each other without falling victim to their violent fellow citizens.