In the middle of a the beautiful harbor of Sydney, on the eve of the biggest public live music party of the year, a body is discovered ravaged by an mysterious contagion and Chief Medical Examiner Jim (Grant Bowler) immediately appeals for quarantine. But the party's too important to the city's coffers to cancel and Jim's fears for the public become personal when he learns his children Elmo (Christian Byers) and Nina (Jessica Tovey) are both at the event.
With the help of government spook Hirsch (Vince Colosimo), Jim takes the law into his own hands and closes off all access to the event. But instead of controlling the situation, a riot erupts that throws the entire city into bedlam. With the world collapsing around him, Jim discovers that not only has his wife Denny (Dee Smart) infiltrated the deadly pandemonium to find their children, but the virus is no accident, and the people responsible for it are the last he'd ever suspect…