A lighthouse keeper is awoken to the sound of women singing on the shore; a group of shape shifting creatures known as selkies have come to shore to dance under the full moon. He catches the eye of one of them on the beach, and they begin a passionate romance. After they are married, a series of increasingly disturbing events and the isolation of living at the lighthouse have The Selkie discomfited. When she becomes pregnant she begins to remember snippets of her old life in the sea, and realizes her husband is not the gentle man she presumed him to be.