As Lilly Franklin prepares to board a shuttle with her husband and son in the face of an impending asteroid strike, she’s approached by a child who is on her own and scared. In a moment of weakness, Lilly gives up her seat to the girl. Alone, she heads for a safe haven.

Hundreds of miles away, Maggie Keller, Lilly’s former best friend, lives with regret over the marriage she left college for. With impending disaster looming, her volatile husband disappears to join a dangerous organization that formed in the shadows of this changing world. Maggie sets out on a mission to find him.

Both Lilly and Maggie navigate back to the Minnesota Northwoods, where they attended college together. There, they meet and unite with others who have stayed behind, including Lilly’s cousin Zane, who has strong feelings for Maggie. He also has tickets for another shuttle launch. For Lilly, this means one last chance to get back to her family. But they must get past Maggie’s husband and his dangerous group, which could give Maggie an opportunity to reclaim all he has taken from her.