In Australia, an elderly couple with an interest in astronomy spots an unexpected comet, soon dubbed Henwood 1. There's a bit of panic but not much as the comet is expected to miss Earth. Instead, it smashes into the moon and vaporizes. But when it dissolves, it emits a pathogen that travels to Earth and infects the population. Den is a Viet Nam veteran, changed by what he saw as a sniper and helicopter pilot in the war. As people begin to die around him, he struggles to survive-at any cost. The Australian Parliamentary tries to ensure that a democratic system endures as a Justice Enforcement group secures all available weapons, but theirs is a losing battle as humanity dissolves. Following the death of his wife, Den searches for his son and remaining family amidst the chaos. He's an old dog, but he does learn new tricks and, unfortunately, remembers how to kill. Soon, a fanatical vicar steps forward and encourages murder among his acolytes. Who will survive this new world order, or is the Earth and all its inhabitants doomed to extinction?