Gamache earns the displeasure of General Director Francoeur when he ignores his superior’s orders and begins investigating the disappearance of Blue Two-Rivers. As a punishment, he’s dispatched to the remote village of Three Pines to investigate the murder of a wealthy socialite named CC de Poitiers, where he soon discovers everything is not as it seems and he has no shortage of suspects.

Gamache realises that the key to solving CC’s murder lies in her enigmatic past. Discovering that one of the villagers has withheld from him a key piece of information, he is able to crack the case. Meanwhile, Gamache’s delight at making a breakthrough in Blue’s disappearance is short-lived as the Two-Rivers family rejects his evidence and the anguished Missy is driven into a desperate act.

Gamache returns to Three Pines to investigate the disappearance of the popular resident Marc Fortier but it soon becomes a murder case that leads Gamache and his team into the heart of the village’s dark past at St Anthony’s. Meanwhile, Lacoste discovers a key piece of evidence relating to Blue’s disappearance has been faked, and with Gamache’s encouragement secretly reopens the case.

The villagers confront the truth of their past and exorcise their collective demons as Gamache makes a breakthrough in the murder case and realises Marc’s killer had a very personal motive. Meanwhile, Lacoste makes a discovery relating to Blue’s disappearance that seems to identify a key suspect.

When a man bent on vengeance is discovered in the woods near Three Pines, seemingly the victim of a group lynching, Gamache finds himself wondering whether all the villagers are capable of murder. Meanwhile, Gamache’s investigation into Blue’s disappearance leads to a terrible discovery that turns Gamache’s world upside down.

Gamache and his team unearth a tragic story that provides the key to the victim’s desire for vengeance, and by doing so leads the team to his murderers. Meanwhile, it falls to Gamache to apprehend the individual responsible for Blue Two-Rivers’ disappearance, putting himself in grave danger as he does so.