After burying his mother, Enoch Carter drives home through relentless rain with the rest of his family, only to face a nightmare as people around him turn feral, craving nothing but relentless carnage. Across the border, Officer Elias Vargas witnesses his city collapse as neighbors, friends, and fellow officers turn violently against one another. The thin line holding society together is gone, and chaos spreads without reason or mercy.

As they journey through the United States and Mexico to save their family—and themselves—new revelations emerge, and an even greater storm looms over the world.