Books in the The Martensen Chronicles series

After the Catastrophe, an analyst is imprisoned as a co-conspirator. His son survives the rise of city-states. Martin infiltrates a white supremacist militia, declares war, becoming The Filtrator, and attempts to rescue an enslaved family.

Homesteaders in Saskatchewan are a hardy breed, threatened by the weather, World War I, and the Spanish Flu. The grandson of the homesteader, Radioman, ships out to Iwo Jima, navigating the remnants of the Great Depression and World War II.