Melbourne's streets are being terrorised by thugs committing crimes of random violence. Someone needs to take a stand. The police, under constant attack from the media, are valiantly fighting the fight. For victims of crime, it's not good enough. But is vigilantism the answer? When a number of known violent offenders are coldly gunned down, it looks like a vengeful predator has taken the law into his own hands. But figuring out the motive doesn't necessarily mean figuring out the culprit and our team will have their work cut out for them to catch this killer. When evidence points to the families of the victims of known violent offenders as principal suspects the case becomes particularly tough for Detective Buchanan, who despite himself starts to empathise with a killer.