Superintendent Stella Gibson (Gillian Anderson), a Senior Detective from the Met, is seconded to Belfast to supervise a 28 day review into the investigation into the death of Alice Monroe. A.C.C. Jim Burns (John Lynch) recommends Stella view the case as a single entity, rather than as part of a larger pattern. As reporters begin to descend on Gibson, she is introduced to Sergeant James Olson (Ben Peel); giving him details of her hotel.
Respectable family-man Paul Spector (Jamie Dornan), meanwhile, continues to stalk Sarah Kay (Laura Donnelly) – a young lawyer, determined to make her his next victim.