Fionn Boyle and his older sister Tara have been sent to stay with their grandfather on the remote island of Arranmore for the summer. Though Fionn has never met his grandfather before - an eccentric old man who lives in a tiny cottage filled to the brim with candles - he knows he comes from a long line of brave lifeboat men, who wear the sea behind their eyes. Fionn is scared of the sea. He has no interest in adventure or shipwrecks or the restless wind that rustles through the island, as though in search of something. But an old magic is stirring deep inside the layers of Arranmore, and it is calling out to Fionn.