Prince Cavan is sure his younger brother, Swane, is behind the children going missing in the city. But his father refuses to listen and sends him away to investigate reports of selkies stealing people from the countryside. A furious Cavan fears this is part of a conspiracy. But then he meets Fallon, a simple country sergeant who has his own theories about the attacks on Gaelland. And what they cannot achieve apart, they must just do together ...