Nathan and his family are on the run from a catastrophic polar shift?but the bitter cold is the least of their worries.

Nathan was led to believe Detroit would be the Promised Land, but when his family arrives they find a city struggling just to survive frigid conditions. Nathan's old friend Stryker has made a safe haven in the ancient Masonic Building, but it soon becomes clear the comfortable life within his walls is unsustainable. Resources are running out fast, and with a new baby to feed and a son in need of medicine, Nathan and Cyndi face a difficult choice: dig in with the dangerously naïve Stryker or head west to Wyoming with their friends Donie and Dave.

As Nathan debates this fateful decision, he learns the horrifying secret behind Stryker's success. He knows deep down that he is unwilling to pay such a price for his family's safety, but leaving the city is no easy matter when even the walls have eyes. Now, his family, Syd, and their friends will have to use all their skills to help each other escape, or die trying.