It began with a dead bird. Then state-wide school closure. Before long, the whole town is in lockdown and the Brooks family are quarantined in their own home — with a faceless enemy on their doorstep. They must cope as best they can, battling hunger, cold and boredom. But as the threat inches closer, and neighbour turns against neighbour, single mother Ann doesn't know who she can trust — including those taking refuge in her house. With no end in sight, Ann knows that if she is to protect her daughters from untold danger, she must make impossible decisions in order to survive...