在发现各自的另一半是兄妹后，这两个心怀怨恨的前恋人必须在同一屋檐下度过圣诞节，同时隐瞒他们的恋爱史。

In a pandemic-stricken world, Stan and Cindy lead a group of strangers thrown together as they attempt to escape northward away from the inflicted known as the Crossed, those affected by a mysterious disease appear to have a cross on their foreheads, and follow their worst impulses.