On a wild Scottish island, a tragedy washes up on the storm-beaten shore: the bodies of a whale and a man. Fraser, desperate for adventure, and Hayley, visiting from Texas, become tangled in the mystery. But Fraser's younger brother Dunny is distraught by the discovery. He hasn't spoken in years, and lately he's been acting more strangely than ever. Together, the three meet a man living in the abandoned caves nearby. They start to wonder if he might lie at the center of something darker than they had previously thought. For the whispering sea conceals a terrible secret, and to discover the truth, one of them must learn to listen.