Seventeen-year-old Vanessa Sands is afraid of everything—the dark, heights, the ocean—but her fearless older sister, Justine, is always there to guide her through every challenge. Until Justine goes cliff diving one night near the family's vacation home in Winter Harbor, and her lifeless body washes up on the beach the next day. Vanessa's parents try to cope with the tragedy by returning to their daily lives in Boston, but she feels her sister's death was no accident. After discovering Justine was hiding several secrets, Vanessa returns to Winter Harbor, hoping that Caleb, her sister's boyfriend, can shed some light, but the boy is missing. Soon, it's not just Vanessa who's afraid. All of Winter Harbor is in turmoil when another body washes up on the beach, and panic sets in as the small town becomes the scene of a series of fatal water-related accidents, in which victims are found grinning horribly from ear to ear. Vanessa and Simon, Caleb's older brother, join forces to investigate the strange occurrences, and along the way, their childhood friendship blossoms into something more. As they uncover links between Justine's death and the sudden rash of terrifying drownings in the town, Vanessa uncovers a secret that threatens her romance with Simon—and will change her life forever.
