Ten-year-old Sara Campbell has strict rules to follow at home ever since her mother died from Double X–a lethal virus that affects only women and has now killed 96 percent of the world’s female population. Sara, like every other surviving female, is permanently confined to her home by law in an attempt to contain the spread of the virus.
Sara’s father, Will, is finding it increasingly difficult to find food for his daughter and must leave her alone and vulnerable to attacks by ransacking vandals. When they flee the city, Sara and Will decide to seek refuge at the family farm in Jefferson, Iowa. Arriving at the farm, Will learns that his mother has died of the virus and his father of a broken heart. The only two left are Will’s brother, Rick, and his wife, Kate.
Rick is displeased by Will’s sudden appearance on the farm, concerned about having more mouths to feed and fearing the presence of more people on the farm will endanger his wife. But when Kate begs him to let Sara and Will stay, Rick agrees to a trial period–a choice that will turn his whole world upside down by a triangle of love.