Ellis Kimball is prepared for every way the world could end. What she doesn't expect is meeting Hannah Marks, the only girl who knows how it's going to happen. Despite Ellis's anxiety, the two girls become fast friends. But time is ticking down, and as Ellis tries to help Hannah decipher the details of her doomsday premonition, their search for answers only raises more questions. When does it happen? Who will believe them? How do you prepare for the end of the world when it feels like your life is just getting started?