It's been 10 years since the big boom, a nuclear event that shook the United States to its core, and wiped out around half of the population. While nobody seems to know for sure what happened, the survivors remember the day that everyone turned into their greatest fears and society collapsed.

Althea follows the lives of the forgotten children in this catastrophe, as they grow and learn to adapt to the new world and cope with the way of living that has been thrust upon them.