After the almost complete annihilation of humankind, small pockets of survivors remain in the southern hemisphere, clinging to life. Except for those fortunate enough to find a place behind the walls. Imogen returns to the refugee camp in the Australian outback to look for her mother, Pippa and is devastated by what she discovers. While within the confines of 'the wall', her husband Teb adjusts to his life as a doctor under the new regime. Greg, his sister Tilly, and a group of friends are on the run from the authorities in New Zealand when they discover an insurmountable enemy. In this post-apocalyptic world, they all struggle to survive and adjust to the different systems while overcoming personal demons and discovering the nature and true intent of their formidable adversaries. If they fail to learn and establish a new way of being, the whole of humankind will collapse.