Twins Virginia and Tommy Matthews have been on their own since they were orphaned at the age of five, surviving a merciless foster care system by relying on each other. Twelve years later, the world begins to collapse around them as a deadly contagion steadily wipes out entire populations and a devastating world war rages on. When Tommy is drafted for the war, the twins are faced with a choice: accept their fate of almost certain death, or dodge the draft. Virginia and Tommy flee into the dark night. Armed with only a pistol and their fierce will to survive, the twins set forth in search of a new beginning. They must navigate the dangers and wonders of this changed world as they try to outrun the demons of their past.

It starts as an ordinary day in an ordinary town, at an ordinary air show. But when one of the planes crashes, killing and injuring dozens, a 13-year-old named Ava is discovered healing her best friend, Wash. Her secret gift is now known to the entire world, and Ava is thrust into the spotlight. But at what cost does this gift come, and how much will Ava have to sacrifice to save the one she loves most?

In their old age, Harold and Lucille have settled comfortably into life without their son, who died tragically at his eighth birthday party in 1966. But then one day, Jacob mysteriously appears on their doorstep --- still eight years old. All over the world, people's loved ones are returning from beyond. The Hargraves are forced to navigate a mysterious new reality and a conflict that threatens to unravel the very meaning of what it is to be human.