As this is Douglas Henshall's final series, his portrayal of is more world-weary than ever.
– Pérez confronts his own past when an old acquaintance from his time in the Metropolitan Police appears on the island, claiming to be investigating a separate, high‑profile kidnapping case that may intersect with the current murder.
– The victim is identified as the sister of a resident fisherman, Finn Haldane, who has a fraught history with the community after a controversial fishing licence dispute. Finn becomes a suspect, not only because of his proximity but also due to his public outburst at the victim’s funeral.