Off the west coast of Ireland lies a lonely island, isolated and wilfully forgotten. Some say there hasn't been a child born on the island for thirty years. Others speak of strange deaths there, decades ago. But no one really knows what happened. Locals believe that the dark times are behind them.

They are mistaken.

Grace, adopted at four years old, has never known where she came from. A mysterious phone call leads her back to the island where she was born – and where a terrible evil has been disturbed.

As the evil starts to spread, Grace finds herself dragged back into a living nightmare that threatens to engulf anyone who steps into its path.