When Detective Inspector Jack Lennon tries to track down his former lover Marie McKenna and their daughter, his superiors tell him to back off. But now an assassin stalks Belfast, tying up loose ends for a vengeance-driven old man. As Lennon unravels a conspiracy that links his daughter to a killer named Fegan, the line between friend and enemy blurs.

Belfast, 1988. A man is found dead, killed with a bolt from a crossbow in front of his house. This is no hunting accident. But uncovering who is responsible for the murder will take Detective Sean Duffy down his most dangerous road yet, a road that leads to a lonely clearing on a high bog where three masked gunmen will force Duffy to dig his own grave. Hunted by forces unknown, threatened by Internal Affairs, and with his relationship on the rocks,...