The Sparrow family is falling apart, and now their city is too. When Portland is hit by the Cascadia Subduction Zone earthquake, siblings Morgan, Olivia, and Sherman are tasked with keeping their family alive following one of the worst natural disasters in living memory.

Being a Sparrow child has never been simple. Olivia, Sherman, and Morgan all have their faults, and they all cope with their tumultuous childhood in their own unstable ways: Olivia leads an excessive lifestyle, Morgan cycles through risky behaviors, and Sherman dabbles in morally precarious business practices. Up until now, they have kept their family from completely crumbling; but the cracks in their relationships are about to be unearthed. As their shaky foundations collide, an earthquake levels their city.

Olivia treks across a mutilated Portland to reach her family; Sherman finds it in himself to protect his siblings from militia looters and thugs; and Morgan uncovers the past wrongs of her parents. To make matters worse, their shelter is in the path of a mass of loose earth repeatedly shaken by aftershocks.

When the siblings finally reunite, their new task is to survive long enough to be medevaced from their childhood home in the face of an impending landslide. Previously separated by secrets and resentments, they realize they are now united by survival. If resources don't run out, if sickness doesn't overtake them, if alt-right militia members don't intervene, and if the wet mass of land speeding toward their makeshift shelter doesn't bury them, they will have to navigate their past traumas and their parents' mistakes. Only then can they honor those they have lost--and survive as a family.