On a two-week beach vacation, Kate Baker's daughter, Olivia, vanishes among the waves. But the next moment, Olivia resurfaces, joyously splashing. What would I do if she didn't come up? Kate wonders. How would I live without her? In another set of circumstances, Kate doesn't have to wonder. Because in that "other" world, Olivia doesn't come back up. Told in parallel timelines, Kate begins to live two lives. In the reality that follows her daughter's death, she maneuvers through every mother's worst nightmare. In her alternate timeline, while she explores a romance with her friend Jason, she finds the line between joy and loss seems to get thinner each day.