Anna Walker, a top writer for a popular London literary agency, is going through a creative crisis. Her manuscript is talentless; the literary agent is one step away from breaking the contract; and the man she loves, instead of supporting Anna, is growing cold and pulling away. Ms. Walker chooses the most remote corner of Northern Ireland and sets off on a long journey to a mysterious island. Rathlin meets her with off-season storms and fogs. Besides fog and bad weather, there is also a picturesque cliff above the ocean, grim swamps, and a strange hotel where—on one of the nights—a terrible murder takes place.