Ishmael Morgan was six years old when her mother-a long-distance swimmer-disappeared into the ocean. To comfort her, Ishmael's father told her that her mother didn't die but simply swam off into the sunset as a mermaid. Ishmael hadn't thought much of that tender lie until early one morning-while speeding down a Mexican highway after a fight with her fiance-her truck plunges off a cliff. But Ishmael doesn't die: she is rescued. When Ishmael awakens, her memories post-accident are of impossible things. She's sure they must be hallucinations; since she seems to remember watching her own legs turn into a tail. Testing her theory-while putting off returning to her old life, including her cancelled wedding-Ishmael dives into the mystery of her new life. What if her father's stories about her mother weren't just stories he told to ease her grief? Seeking answers to her past, as well as her future, Ishmael begins a trek across land and sea into a life she hasn't even begun to imagine.