Alex Galbraith is shot dead on the same day as Pérez's mother's funeral. Their investigation is interfered by Fraser Creggan. A pipeline worker Eamon Gauldie informs Pérez that he has evidence on his drone that can identify Galbraith's killer.
Douglas Henshall returns in the detective drama. Perez attends his mother's funeral on Fair Isle, where he begins to worry that his father is having trouble with his memory. However, when Tosh calls to inform him of a murder - the shooting of a prominent and controversial Shetlander on their doorstep in broad daylight - he rushes back to lead the investigation.