In memory of her mother's early death, Nancy (Blake Lively) comes to the beach that has a different meaning to her mother, and prepares to do a surfing sport here. With a secluded environment, clear sea water, warm sunshine, and active waterbirds, Nancy deeply feels that this is a blessed land given by God to her and her mother. While surfing, Nancy accidentally discovered the body of a whale that had been attacked by a shark and unfortunately died. This ominous scene foreshadowed the terrible experience she was about to face. The smell of corpses attracted sharks from afar...