If you knew the world was ending, what would you want your children to know about survival? What would you sacrifice to protect them? What secrets would you want to stay buried?

For Olivia Sullivan, the summer of 2024, was the beginning of the end. The news is constantly reporting on political upheavals and natural disasters, food and gas shortages are becoming more frequent, and southern California is unbearably hot. Soon Olivia becomes obsessed with doomsday prepping, spending hours on forums determined to protect her children from the coming apocalypse. Her husband and friends insist she’s being irrational, but then Olivia is swept away in a flash flood that wiped out half of LA.

Or that’s the story Rosie, Bettie, and Cassie were told.

Twenty years later, the sisters discover a box of their mother’s belongings that calls into question everything they’re father has told them about their mother, including if she really died. Reeling from their father’s betrayal the family returns to California determined to uncover Olivia’s true fate. Confronted by a world unlike anything they’ve ever known, where no one quite seems to be telling the truth and danger hangs heavy in the air, the Sullivan triplets find themselves struggling with questions about the father who raised them and the mother who may have abandoned them, all while trying to hold onto the only constant in their lives—each other.