Agatha is a Hawk. It's her job to keep watch and defend her isolated settlement against invasion from across the sea, and she is good at it. But she is also different, and that makes her position in her beloved clan precarious.
When terror arrives Agatha sets out on a journey to rescue her stolen and enslaved people; she and her friend Jaime must face murderous enemies, hardship and betrayal, tests of strength and courage and – most terrifying of all – the sgailean, whispering shadow-creatures which live to kill. At last Agatha begins to understand her own power; but will she be in time to save everything she loves?