All six episodes from the eighth series of the Scottish crime drama based on the novels by Ann Cleeves, starring Ashley Jensen as Detective Inspector Ruth Calder. When a police informant is murdered in London and the only witness flees to Shetland, DI Calder, who grew up on the island, returns there to find her. Meanwhile, Detective Sergeant Alison 'Tosh' Macintosh (Alison O'Donnell) is investigating the ritualistic killing of sheep and after the body of the witness is found bearing the same symbol as the dead sheep, they realise the cases are connected and must join forces to uncover the truth.